1//===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file provides Sema routines for C++ overloading.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/CXXInheritance.h"
15#include "clang/AST/DeclObjC.h"
16#include "clang/AST/DependenceFlags.h"
17#include "clang/AST/Expr.h"
18#include "clang/AST/ExprCXX.h"
19#include "clang/AST/ExprObjC.h"
20#include "clang/AST/TypeOrdering.h"
21#include "clang/Basic/Diagnostic.h"
22#include "clang/Basic/DiagnosticOptions.h"
23#include "clang/Basic/PartialDiagnostic.h"
24#include "clang/Basic/SourceManager.h"
25#include "clang/Basic/TargetInfo.h"
26#include "clang/Sema/Initialization.h"
27#include "clang/Sema/Lookup.h"
28#include "clang/Sema/Overload.h"
29#include "clang/Sema/SemaInternal.h"
30#include "clang/Sema/Template.h"
31#include "clang/Sema/TemplateDeduction.h"
32#include "llvm/ADT/DenseSet.h"
33#include "llvm/ADT/Optional.h"
34#include "llvm/ADT/STLExtras.h"
35#include "llvm/ADT/SmallPtrSet.h"
36#include "llvm/ADT/SmallString.h"
37#include <algorithm>
38#include <cstdlib>
39
40using namespace clang;
41using namespace sema;
42
43using AllowedExplicit = Sema::AllowedExplicit;
44
45static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
46 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
47 return P->hasAttr<PassObjectSizeAttr>();
48 });
49}
50
51/// A convenience routine for creating a decayed reference to a function.
52static ExprResult
53CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
54 const Expr *Base, bool HadMultipleCandidates,
55 SourceLocation Loc = SourceLocation(),
56 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
57 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
58 return ExprError();
59 // If FoundDecl is different from Fn (such as if one is a template
60 // and the other a specialization), make sure DiagnoseUseOfDecl is
61 // called on both.
62 // FIXME: This would be more comprehensively addressed by modifying
63 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
64 // being used.
65 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
66 return ExprError();
67 DeclRefExpr *DRE = new (S.Context)
68 DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo);
69 if (HadMultipleCandidates)
70 DRE->setHadMultipleCandidates(true);
71
72 S.MarkDeclRefReferenced(DRE, Base);
73 if (auto *FPT = DRE->getType()->getAs<FunctionProtoType>()) {
74 if (isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) {
75 S.ResolveExceptionSpec(Loc, FPT);
76 DRE->setType(Fn->getType());
77 }
78 }
79 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
80 CK_FunctionToPointerDecay);
81}
82
83static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
84 bool InOverloadResolution,
85 StandardConversionSequence &SCS,
86 bool CStyle,
87 bool AllowObjCWritebackConversion);
88
89static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
90 QualType &ToType,
91 bool InOverloadResolution,
92 StandardConversionSequence &SCS,
93 bool CStyle);
94static OverloadingResult
95IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
96 UserDefinedConversionSequence& User,
97 OverloadCandidateSet& Conversions,
98 AllowedExplicit AllowExplicit,
99 bool AllowObjCConversionOnExplicit);
100
101static ImplicitConversionSequence::CompareKind
102CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
103 const StandardConversionSequence& SCS1,
104 const StandardConversionSequence& SCS2);
105
106static ImplicitConversionSequence::CompareKind
107CompareQualificationConversions(Sema &S,
108 const StandardConversionSequence& SCS1,
109 const StandardConversionSequence& SCS2);
110
111static ImplicitConversionSequence::CompareKind
112CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
113 const StandardConversionSequence& SCS1,
114 const StandardConversionSequence& SCS2);
115
116/// GetConversionRank - Retrieve the implicit conversion rank
117/// corresponding to the given implicit conversion kind.
118ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
119 static const ImplicitConversionRank
120 Rank[(int)ICK_Num_Conversion_Kinds] = {
121 ICR_Exact_Match,
122 ICR_Exact_Match,
123 ICR_Exact_Match,
124 ICR_Exact_Match,
125 ICR_Exact_Match,
126 ICR_Exact_Match,
127 ICR_Promotion,
128 ICR_Promotion,
129 ICR_Promotion,
130 ICR_Conversion,
131 ICR_Conversion,
132 ICR_Conversion,
133 ICR_Conversion,
134 ICR_Conversion,
135 ICR_Conversion,
136 ICR_Conversion,
137 ICR_Conversion,
138 ICR_Conversion,
139 ICR_Conversion,
140 ICR_Conversion,
141 ICR_OCL_Scalar_Widening,
142 ICR_Complex_Real_Conversion,
143 ICR_Conversion,
144 ICR_Conversion,
145 ICR_Writeback_Conversion,
146 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
147 // it was omitted by the patch that added
148 // ICK_Zero_Event_Conversion
149 ICR_C_Conversion,
150 ICR_C_Conversion_Extension
151 };
152 return Rank[(int)Kind];
153}
154
155/// GetImplicitConversionName - Return the name of this kind of
156/// implicit conversion.
157static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
158 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
159 "No conversion",
160 "Lvalue-to-rvalue",
161 "Array-to-pointer",
162 "Function-to-pointer",
163 "Function pointer conversion",
164 "Qualification",
165 "Integral promotion",
166 "Floating point promotion",
167 "Complex promotion",
168 "Integral conversion",
169 "Floating conversion",
170 "Complex conversion",
171 "Floating-integral conversion",
172 "Pointer conversion",
173 "Pointer-to-member conversion",
174 "Boolean conversion",
175 "Compatible-types conversion",
176 "Derived-to-base conversion",
177 "Vector conversion",
178 "SVE Vector conversion",
179 "Vector splat",
180 "Complex-real conversion",
181 "Block Pointer conversion",
182 "Transparent Union Conversion",
183 "Writeback conversion",
184 "OpenCL Zero Event Conversion",
185 "C specific type conversion",
186 "Incompatible pointer conversion"
187 };
188 return Name[Kind];
189}
190
191/// StandardConversionSequence - Set the standard conversion
192/// sequence to the identity conversion.
193void StandardConversionSequence::setAsIdentityConversion() {
194 First = ICK_Identity;
195 Second = ICK_Identity;
196 Third = ICK_Identity;
197 DeprecatedStringLiteralToCharPtr = false;
198 QualificationIncludesObjCLifetime = false;
199 ReferenceBinding = false;
200 DirectBinding = false;
201 IsLvalueReference = true;
202 BindsToFunctionLvalue = false;
203 BindsToRvalue = false;
204 BindsImplicitObjectArgumentWithoutRefQualifier = false;
205 ObjCLifetimeConversionBinding = false;
206 CopyConstructor = nullptr;
207}
208
209/// getRank - Retrieve the rank of this standard conversion sequence
210/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
211/// implicit conversions.
212ImplicitConversionRank StandardConversionSequence::getRank() const {
213 ImplicitConversionRank Rank = ICR_Exact_Match;
214 if (GetConversionRank(First) > Rank)
215 Rank = GetConversionRank(First);
216 if (GetConversionRank(Second) > Rank)
217 Rank = GetConversionRank(Second);
218 if (GetConversionRank(Third) > Rank)
219 Rank = GetConversionRank(Third);
220 return Rank;
221}
222
223/// isPointerConversionToBool - Determines whether this conversion is
224/// a conversion of a pointer or pointer-to-member to bool. This is
225/// used as part of the ranking of standard conversion sequences
226/// (C++ 13.3.3.2p4).
227bool StandardConversionSequence::isPointerConversionToBool() const {
228 // Note that FromType has not necessarily been transformed by the
229 // array-to-pointer or function-to-pointer implicit conversions, so
230 // check for their presence as well as checking whether FromType is
231 // a pointer.
232 if (getToType(1)->isBooleanType() &&
233 (getFromType()->isPointerType() ||
234 getFromType()->isMemberPointerType() ||
235 getFromType()->isObjCObjectPointerType() ||
236 getFromType()->isBlockPointerType() ||
237 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
238 return true;
239
240 return false;
241}
242
243/// isPointerConversionToVoidPointer - Determines whether this
244/// conversion is a conversion of a pointer to a void pointer. This is
245/// used as part of the ranking of standard conversion sequences (C++
246/// 13.3.3.2p4).
247bool
248StandardConversionSequence::
249isPointerConversionToVoidPointer(ASTContext& Context) const {
250 QualType FromType = getFromType();
251 QualType ToType = getToType(1);
252
253 // Note that FromType has not necessarily been transformed by the
254 // array-to-pointer implicit conversion, so check for its presence
255 // and redo the conversion to get a pointer.
256 if (First == ICK_Array_To_Pointer)
257 FromType = Context.getArrayDecayedType(FromType);
258
259 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
260 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
261 return ToPtrType->getPointeeType()->isVoidType();
262
263 return false;
264}
265
266/// Skip any implicit casts which could be either part of a narrowing conversion
267/// or after one in an implicit conversion.
268static const Expr *IgnoreNarrowingConversion(ASTContext &Ctx,
269 const Expr *Converted) {
270 // We can have cleanups wrapping the converted expression; these need to be
271 // preserved so that destructors run if necessary.
272 if (auto *EWC = dyn_cast<ExprWithCleanups>(Converted)) {
273 Expr *Inner =
274 const_cast<Expr *>(IgnoreNarrowingConversion(Ctx, EWC->getSubExpr()));
275 return ExprWithCleanups::Create(Ctx, Inner, EWC->cleanupsHaveSideEffects(),
276 EWC->getObjects());
277 }
278
279 while (auto *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
280 switch (ICE->getCastKind()) {
281 case CK_NoOp:
282 case CK_IntegralCast:
283 case CK_IntegralToBoolean:
284 case CK_IntegralToFloating:
285 case CK_BooleanToSignedIntegral:
286 case CK_FloatingToIntegral:
287 case CK_FloatingToBoolean:
288 case CK_FloatingCast:
289 Converted = ICE->getSubExpr();
290 continue;
291
292 default:
293 return Converted;
294 }
295 }
296
297 return Converted;
298}
299
300/// Check if this standard conversion sequence represents a narrowing
301/// conversion, according to C++11 [dcl.init.list]p7.
302///
303/// \param Ctx The AST context.
304/// \param Converted The result of applying this standard conversion sequence.
305/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
306/// value of the expression prior to the narrowing conversion.
307/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
308/// type of the expression prior to the narrowing conversion.
309/// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
310/// from floating point types to integral types should be ignored.
311NarrowingKind StandardConversionSequence::getNarrowingKind(
312 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
313 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
314 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
315
316 // C++11 [dcl.init.list]p7:
317 // A narrowing conversion is an implicit conversion ...
318 QualType FromType = getToType(0);
319 QualType ToType = getToType(1);
320
321 // A conversion to an enumeration type is narrowing if the conversion to
322 // the underlying type is narrowing. This only arises for expressions of
323 // the form 'Enum{init}'.
324 if (auto *ET = ToType->getAs<EnumType>())
325 ToType = ET->getDecl()->getIntegerType();
326
327 switch (Second) {
328 // 'bool' is an integral type; dispatch to the right place to handle it.
329 case ICK_Boolean_Conversion:
330 if (FromType->isRealFloatingType())
331 goto FloatingIntegralConversion;
332 if (FromType->isIntegralOrUnscopedEnumerationType())
333 goto IntegralConversion;
334 // -- from a pointer type or pointer-to-member type to bool, or
335 return NK_Type_Narrowing;
336
337 // -- from a floating-point type to an integer type, or
338 //
339 // -- from an integer type or unscoped enumeration type to a floating-point
340 // type, except where the source is a constant expression and the actual
341 // value after conversion will fit into the target type and will produce
342 // the original value when converted back to the original type, or
343 case ICK_Floating_Integral:
344 FloatingIntegralConversion:
345 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
346 return NK_Type_Narrowing;
347 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
348 ToType->isRealFloatingType()) {
349 if (IgnoreFloatToIntegralConversion)
350 return NK_Not_Narrowing;
351 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
352 assert(Initializer && "Unknown conversion expression");
353
354 // If it's value-dependent, we can't tell whether it's narrowing.
355 if (Initializer->isValueDependent())
356 return NK_Dependent_Narrowing;
357
358 if (Optional<llvm::APSInt> IntConstantValue =
359 Initializer->getIntegerConstantExpr(Ctx)) {
360 // Convert the integer to the floating type.
361 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
362 Result.convertFromAPInt(*IntConstantValue, IntConstantValue->isSigned(),
363 llvm::APFloat::rmNearestTiesToEven);
364 // And back.
365 llvm::APSInt ConvertedValue = *IntConstantValue;
366 bool ignored;
367 Result.convertToInteger(ConvertedValue,
368 llvm::APFloat::rmTowardZero, &ignored);
369 // If the resulting value is different, this was a narrowing conversion.
370 if (*IntConstantValue != ConvertedValue) {
371 ConstantValue = APValue(*IntConstantValue);
372 ConstantType = Initializer->getType();
373 return NK_Constant_Narrowing;
374 }
375 } else {
376 // Variables are always narrowings.
377 return NK_Variable_Narrowing;
378 }
379 }
380 return NK_Not_Narrowing;
381
382 // -- from long double to double or float, or from double to float, except
383 // where the source is a constant expression and the actual value after
384 // conversion is within the range of values that can be represented (even
385 // if it cannot be represented exactly), or
386 case ICK_Floating_Conversion:
387 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
388 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
389 // FromType is larger than ToType.
390 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
391
392 // If it's value-dependent, we can't tell whether it's narrowing.
393 if (Initializer->isValueDependent())
394 return NK_Dependent_Narrowing;
395
396 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
397 // Constant!
398 assert(ConstantValue.isFloat());
399 llvm::APFloat FloatVal = ConstantValue.getFloat();
400 // Convert the source value into the target type.
401 bool ignored;
402 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
403 Ctx.getFloatTypeSemantics(ToType),
404 llvm::APFloat::rmNearestTiesToEven, &ignored);
405 // If there was no overflow, the source value is within the range of
406 // values that can be represented.
407 if (ConvertStatus & llvm::APFloat::opOverflow) {
408 ConstantType = Initializer->getType();
409 return NK_Constant_Narrowing;
410 }
411 } else {
412 return NK_Variable_Narrowing;
413 }
414 }
415 return NK_Not_Narrowing;
416
417 // -- from an integer type or unscoped enumeration type to an integer type
418 // that cannot represent all the values of the original type, except where
419 // the source is a constant expression and the actual value after
420 // conversion will fit into the target type and will produce the original
421 // value when converted back to the original type.
422 case ICK_Integral_Conversion:
423 IntegralConversion: {
424 assert(FromType->isIntegralOrUnscopedEnumerationType());
425 assert(ToType->isIntegralOrUnscopedEnumerationType());
426 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
427 const unsigned FromWidth = Ctx.getIntWidth(FromType);
428 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
429 const unsigned ToWidth = Ctx.getIntWidth(ToType);
430
431 if (FromWidth > ToWidth ||
432 (FromWidth == ToWidth && FromSigned != ToSigned) ||
433 (FromSigned && !ToSigned)) {
434 // Not all values of FromType can be represented in ToType.
435 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
436
437 // If it's value-dependent, we can't tell whether it's narrowing.
438 if (Initializer->isValueDependent())
439 return NK_Dependent_Narrowing;
440
441 Optional<llvm::APSInt> OptInitializerValue;
442 if (!(OptInitializerValue = Initializer->getIntegerConstantExpr(Ctx))) {
443 // Such conversions on variables are always narrowing.
444 return NK_Variable_Narrowing;
445 }
446 llvm::APSInt &InitializerValue = *OptInitializerValue;
447 bool Narrowing = false;
448 if (FromWidth < ToWidth) {
449 // Negative -> unsigned is narrowing. Otherwise, more bits is never
450 // narrowing.
451 if (InitializerValue.isSigned() && InitializerValue.isNegative())
452 Narrowing = true;
453 } else {
454 // Add a bit to the InitializerValue so we don't have to worry about
455 // signed vs. unsigned comparisons.
456 InitializerValue = InitializerValue.extend(
457 InitializerValue.getBitWidth() + 1);
458 // Convert the initializer to and from the target width and signed-ness.
459 llvm::APSInt ConvertedValue = InitializerValue;
460 ConvertedValue = ConvertedValue.trunc(ToWidth);
461 ConvertedValue.setIsSigned(ToSigned);
462 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
463 ConvertedValue.setIsSigned(InitializerValue.isSigned());
464 // If the result is different, this was a narrowing conversion.
465 if (ConvertedValue != InitializerValue)
466 Narrowing = true;
467 }
468 if (Narrowing) {
469 ConstantType = Initializer->getType();
470 ConstantValue = APValue(InitializerValue);
471 return NK_Constant_Narrowing;
472 }
473 }
474 return NK_Not_Narrowing;
475 }
476
477 default:
478 // Other kinds of conversions are not narrowings.
479 return NK_Not_Narrowing;
480 }
481}
482
483/// dump - Print this standard conversion sequence to standard
484/// error. Useful for debugging overloading issues.
485LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
486 raw_ostream &OS = llvm::errs();
487 bool PrintedSomething = false;
488 if (First != ICK_Identity) {
489 OS << GetImplicitConversionName(First);
490 PrintedSomething = true;
491 }
492
493 if (Second != ICK_Identity) {
494 if (PrintedSomething) {
495 OS << " -> ";
496 }
497 OS << GetImplicitConversionName(Second);
498
499 if (CopyConstructor) {
500 OS << " (by copy constructor)";
501 } else if (DirectBinding) {
502 OS << " (direct reference binding)";
503 } else if (ReferenceBinding) {
504 OS << " (reference binding)";
505 }
506 PrintedSomething = true;
507 }
508
509 if (Third != ICK_Identity) {
510 if (PrintedSomething) {
511 OS << " -> ";
512 }
513 OS << GetImplicitConversionName(Third);
514 PrintedSomething = true;
515 }
516
517 if (!PrintedSomething) {
518 OS << "No conversions required";
519 }
520}
521
522/// dump - Print this user-defined conversion sequence to standard
523/// error. Useful for debugging overloading issues.
524void UserDefinedConversionSequence::dump() const {
525 raw_ostream &OS = llvm::errs();
526 if (Before.First || Before.Second || Before.Third) {
527 Before.dump();
528 OS << " -> ";
529 }
530 if (ConversionFunction)
531 OS << '\'' << *ConversionFunction << '\'';
532 else
533 OS << "aggregate initialization";
534 if (After.First || After.Second || After.Third) {
535 OS << " -> ";
536 After.dump();
537 }
538}
539
540/// dump - Print this implicit conversion sequence to standard
541/// error. Useful for debugging overloading issues.
542void ImplicitConversionSequence::dump() const {
543 raw_ostream &OS = llvm::errs();
544 if (isStdInitializerListElement())
545 OS << "Worst std::initializer_list element conversion: ";
546 switch (ConversionKind) {
547 case StandardConversion:
548 OS << "Standard conversion: ";
549 Standard.dump();
550 break;
551 case UserDefinedConversion:
552 OS << "User-defined conversion: ";
553 UserDefined.dump();
554 break;
555 case EllipsisConversion:
556 OS << "Ellipsis conversion";
557 break;
558 case AmbiguousConversion:
559 OS << "Ambiguous conversion";
560 break;
561 case BadConversion:
562 OS << "Bad conversion";
563 break;
564 }
565
566 OS << "\n";
567}
568
569void AmbiguousConversionSequence::construct() {
570 new (&conversions()) ConversionSet();
571}
572
573void AmbiguousConversionSequence::destruct() {
574 conversions().~ConversionSet();
575}
576
577void
578AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
579 FromTypePtr = O.FromTypePtr;
580 ToTypePtr = O.ToTypePtr;
581 new (&conversions()) ConversionSet(O.conversions());
582}
583
584namespace {
585 // Structure used by DeductionFailureInfo to store
586 // template argument information.
587 struct DFIArguments {
588 TemplateArgument FirstArg;
589 TemplateArgument SecondArg;
590 };
591 // Structure used by DeductionFailureInfo to store
592 // template parameter and template argument information.
593 struct DFIParamWithArguments : DFIArguments {
594 TemplateParameter Param;
595 };
596 // Structure used by DeductionFailureInfo to store template argument
597 // information and the index of the problematic call argument.
598 struct DFIDeducedMismatchArgs : DFIArguments {
599 TemplateArgumentList *TemplateArgs;
600 unsigned CallArgIndex;
601 };
602 // Structure used by DeductionFailureInfo to store information about
603 // unsatisfied constraints.
604 struct CNSInfo {
605 TemplateArgumentList *TemplateArgs;
606 ConstraintSatisfaction Satisfaction;
607 };
608}
609
610/// Convert from Sema's representation of template deduction information
611/// to the form used in overload-candidate information.
612DeductionFailureInfo
613clang::MakeDeductionFailureInfo(ASTContext &Context,
614 Sema::TemplateDeductionResult TDK,
615 TemplateDeductionInfo &Info) {
616 DeductionFailureInfo Result;
617 Result.Result = static_cast<unsigned>(TDK);
618 Result.HasDiagnostic = false;
619 switch (TDK) {
620 case Sema::TDK_Invalid:
621 case Sema::TDK_InstantiationDepth:
622 case Sema::TDK_TooManyArguments:
623 case Sema::TDK_TooFewArguments:
624 case Sema::TDK_MiscellaneousDeductionFailure:
625 case Sema::TDK_CUDATargetMismatch:
626 Result.Data = nullptr;
627 break;
628
629 case Sema::TDK_Incomplete:
630 case Sema::TDK_InvalidExplicitArguments:
631 Result.Data = Info.Param.getOpaqueValue();
632 break;
633
634 case Sema::TDK_DeducedMismatch:
635 case Sema::TDK_DeducedMismatchNested: {
636 // FIXME: Should allocate from normal heap so that we can free this later.
637 auto *Saved = new (Context) DFIDeducedMismatchArgs;
638 Saved->FirstArg = Info.FirstArg;
639 Saved->SecondArg = Info.SecondArg;
640 Saved->TemplateArgs = Info.take();
641 Saved->CallArgIndex = Info.CallArgIndex;
642 Result.Data = Saved;
643 break;
644 }
645
646 case Sema::TDK_NonDeducedMismatch: {
647 // FIXME: Should allocate from normal heap so that we can free this later.
648 DFIArguments *Saved = new (Context) DFIArguments;
649 Saved->FirstArg = Info.FirstArg;
650 Saved->SecondArg = Info.SecondArg;
651 Result.Data = Saved;
652 break;
653 }
654
655 case Sema::TDK_IncompletePack:
656 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
657 case Sema::TDK_Inconsistent:
658 case Sema::TDK_Underqualified: {
659 // FIXME: Should allocate from normal heap so that we can free this later.
660 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
661 Saved->Param = Info.Param;
662 Saved->FirstArg = Info.FirstArg;
663 Saved->SecondArg = Info.SecondArg;
664 Result.Data = Saved;
665 break;
666 }
667
668 case Sema::TDK_SubstitutionFailure:
669 Result.Data = Info.take();
670 if (Info.hasSFINAEDiagnostic()) {
671 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
672 SourceLocation(), PartialDiagnostic::NullDiagnostic());
673 Info.takeSFINAEDiagnostic(*Diag);
674 Result.HasDiagnostic = true;
675 }
676 break;
677
678 case Sema::TDK_ConstraintsNotSatisfied: {
679 CNSInfo *Saved = new (Context) CNSInfo;
680 Saved->TemplateArgs = Info.take();
681 Saved->Satisfaction = Info.AssociatedConstraintsSatisfaction;
682 Result.Data = Saved;
683 break;
684 }
685
686 case Sema::TDK_Success:
687 case Sema::TDK_NonDependentConversionFailure:
688 llvm_unreachable("not a deduction failure");
689 }
690
691 return Result;
692}
693
694void DeductionFailureInfo::Destroy() {
695 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
696 case Sema::TDK_Success:
697 case Sema::TDK_Invalid:
698 case Sema::TDK_InstantiationDepth:
699 case Sema::TDK_Incomplete:
700 case Sema::TDK_TooManyArguments:
701 case Sema::TDK_TooFewArguments:
702 case Sema::TDK_InvalidExplicitArguments:
703 case Sema::TDK_CUDATargetMismatch:
704 case Sema::TDK_NonDependentConversionFailure:
705 break;
706
707 case Sema::TDK_IncompletePack:
708 case Sema::TDK_Inconsistent:
709 case Sema::TDK_Underqualified:
710 case Sema::TDK_DeducedMismatch:
711 case Sema::TDK_DeducedMismatchNested:
712 case Sema::TDK_NonDeducedMismatch:
713 // FIXME: Destroy the data?
714 Data = nullptr;
715 break;
716
717 case Sema::TDK_SubstitutionFailure:
718 // FIXME: Destroy the template argument list?
719 Data = nullptr;
720 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
721 Diag->~PartialDiagnosticAt();
722 HasDiagnostic = false;
723 }
724 break;
725
726 case Sema::TDK_ConstraintsNotSatisfied:
727 // FIXME: Destroy the template argument list?
728 Data = nullptr;
729 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
730 Diag->~PartialDiagnosticAt();
731 HasDiagnostic = false;
732 }
733 break;
734
735 // Unhandled
736 case Sema::TDK_MiscellaneousDeductionFailure:
737 break;
738 }
739}
740
741PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
742 if (HasDiagnostic)
743 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
744 return nullptr;
745}
746
747TemplateParameter DeductionFailureInfo::getTemplateParameter() {
748 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
749 case Sema::TDK_Success:
750 case Sema::TDK_Invalid:
751 case Sema::TDK_InstantiationDepth:
752 case Sema::TDK_TooManyArguments:
753 case Sema::TDK_TooFewArguments:
754 case Sema::TDK_SubstitutionFailure:
755 case Sema::TDK_DeducedMismatch:
756 case Sema::TDK_DeducedMismatchNested:
757 case Sema::TDK_NonDeducedMismatch:
758 case Sema::TDK_CUDATargetMismatch:
759 case Sema::TDK_NonDependentConversionFailure:
760 case Sema::TDK_ConstraintsNotSatisfied:
761 return TemplateParameter();
762
763 case Sema::TDK_Incomplete:
764 case Sema::TDK_InvalidExplicitArguments:
765 return TemplateParameter::getFromOpaqueValue(Data);
766
767 case Sema::TDK_IncompletePack:
768 case Sema::TDK_Inconsistent:
769 case Sema::TDK_Underqualified:
770 return static_cast<DFIParamWithArguments*>(Data)->Param;
771
772 // Unhandled
773 case Sema::TDK_MiscellaneousDeductionFailure:
774 break;
775 }
776
777 return TemplateParameter();
778}
779
780TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
781 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
782 case Sema::TDK_Success:
783 case Sema::TDK_Invalid:
784 case Sema::TDK_InstantiationDepth:
785 case Sema::TDK_TooManyArguments:
786 case Sema::TDK_TooFewArguments:
787 case Sema::TDK_Incomplete:
788 case Sema::TDK_IncompletePack:
789 case Sema::TDK_InvalidExplicitArguments:
790 case Sema::TDK_Inconsistent:
791 case Sema::TDK_Underqualified:
792 case Sema::TDK_NonDeducedMismatch:
793 case Sema::TDK_CUDATargetMismatch:
794 case Sema::TDK_NonDependentConversionFailure:
795 return nullptr;
796
797 case Sema::TDK_DeducedMismatch:
798 case Sema::TDK_DeducedMismatchNested:
799 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
800
801 case Sema::TDK_SubstitutionFailure:
802 return static_cast<TemplateArgumentList*>(Data);
803
804 case Sema::TDK_ConstraintsNotSatisfied:
805 return static_cast<CNSInfo*>(Data)->TemplateArgs;
806
807 // Unhandled
808 case Sema::TDK_MiscellaneousDeductionFailure:
809 break;
810 }
811
812 return nullptr;
813}
814
815const TemplateArgument *DeductionFailureInfo::getFirstArg() {
816 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
817 case Sema::TDK_Success:
818 case Sema::TDK_Invalid:
819 case Sema::TDK_InstantiationDepth:
820 case Sema::TDK_Incomplete:
821 case Sema::TDK_TooManyArguments:
822 case Sema::TDK_TooFewArguments:
823 case Sema::TDK_InvalidExplicitArguments:
824 case Sema::TDK_SubstitutionFailure:
825 case Sema::TDK_CUDATargetMismatch:
826 case Sema::TDK_NonDependentConversionFailure:
827 case Sema::TDK_ConstraintsNotSatisfied:
828 return nullptr;
829
830 case Sema::TDK_IncompletePack:
831 case Sema::TDK_Inconsistent:
832 case Sema::TDK_Underqualified:
833 case Sema::TDK_DeducedMismatch:
834 case Sema::TDK_DeducedMismatchNested:
835 case Sema::TDK_NonDeducedMismatch:
836 return &static_cast<DFIArguments*>(Data)->FirstArg;
837
838 // Unhandled
839 case Sema::TDK_MiscellaneousDeductionFailure:
840 break;
841 }
842
843 return nullptr;
844}
845
846const TemplateArgument *DeductionFailureInfo::getSecondArg() {
847 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
848 case Sema::TDK_Success:
849 case Sema::TDK_Invalid:
850 case Sema::TDK_InstantiationDepth:
851 case Sema::TDK_Incomplete:
852 case Sema::TDK_IncompletePack:
853 case Sema::TDK_TooManyArguments:
854 case Sema::TDK_TooFewArguments:
855 case Sema::TDK_InvalidExplicitArguments:
856 case Sema::TDK_SubstitutionFailure:
857 case Sema::TDK_CUDATargetMismatch:
858 case Sema::TDK_NonDependentConversionFailure:
859 case Sema::TDK_ConstraintsNotSatisfied:
860 return nullptr;
861
862 case Sema::TDK_Inconsistent:
863 case Sema::TDK_Underqualified:
864 case Sema::TDK_DeducedMismatch:
865 case Sema::TDK_DeducedMismatchNested:
866 case Sema::TDK_NonDeducedMismatch:
867 return &static_cast<DFIArguments*>(Data)->SecondArg;
868
869 // Unhandled
870 case Sema::TDK_MiscellaneousDeductionFailure:
871 break;
872 }
873
874 return nullptr;
875}
876
877llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
878 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
879 case Sema::TDK_DeducedMismatch:
880 case Sema::TDK_DeducedMismatchNested:
881 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
882
883 default:
884 return llvm::None;
885 }
886}
887
888bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
889 OverloadedOperatorKind Op) {
890 if (!AllowRewrittenCandidates)
891 return false;
892 return Op == OO_EqualEqual || Op == OO_Spaceship;
893}
894
895bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
896 ASTContext &Ctx, const FunctionDecl *FD) {
897 if (!shouldAddReversed(FD->getDeclName().getCXXOverloadedOperator()))
898 return false;
899 // Don't bother adding a reversed candidate that can never be a better
900 // match than the non-reversed version.
901 return FD->getNumParams() != 2 ||
902 !Ctx.hasSameUnqualifiedType(FD->getParamDecl(0)->getType(),
903 FD->getParamDecl(1)->getType()) ||
904 FD->hasAttr<EnableIfAttr>();
905}
906
907void OverloadCandidateSet::destroyCandidates() {
908 for (iterator i = begin(), e = end(); i != e; ++i) {
909 for (auto &C : i->Conversions)
910 C.~ImplicitConversionSequence();
911 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
912 i->DeductionFailure.Destroy();
913 }
914}
915
916void OverloadCandidateSet::clear(CandidateSetKind CSK) {
917 destroyCandidates();
918 SlabAllocator.Reset();
919 NumInlineBytesUsed = 0;
920 Candidates.clear();
921 Functions.clear();
922 Kind = CSK;
923}
924
925namespace {
926 class UnbridgedCastsSet {
927 struct Entry {
928 Expr **Addr;
929 Expr *Saved;
930 };
931 SmallVector<Entry, 2> Entries;
932
933 public:
934 void save(Sema &S, Expr *&E) {
935 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
936 Entry entry = { &E, E };
937 Entries.push_back(entry);
938 E = S.stripARCUnbridgedCast(E);
939 }
940
941 void restore() {
942 for (SmallVectorImpl<Entry>::iterator
943 i = Entries.begin(), e = Entries.end(); i != e; ++i)
944 *i->Addr = i->Saved;
945 }
946 };
947}
948
949/// checkPlaceholderForOverload - Do any interesting placeholder-like
950/// preprocessing on the given expression.
951///
952/// \param unbridgedCasts a collection to which to add unbridged casts;
953/// without this, they will be immediately diagnosed as errors
954///
955/// Return true on unrecoverable error.
956static bool
957checkPlaceholderForOverload(Sema &S, Expr *&E,
958 UnbridgedCastsSet *unbridgedCasts = nullptr) {
959 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
960 // We can't handle overloaded expressions here because overload
961 // resolution might reasonably tweak them.
962 if (placeholder->getKind() == BuiltinType::Overload) return false;
963
964 // If the context potentially accepts unbridged ARC casts, strip
965 // the unbridged cast and add it to the collection for later restoration.
966 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
967 unbridgedCasts) {
968 unbridgedCasts->save(S, E);
969 return false;
970 }
971
972 // Go ahead and check everything else.
973 ExprResult result = S.CheckPlaceholderExpr(E);
974 if (result.isInvalid())
975 return true;
976
977 E = result.get();
978 return false;
979 }
980
981 // Nothing to do.
982 return false;
983}
984
985/// checkArgPlaceholdersForOverload - Check a set of call operands for
986/// placeholders.
987static bool checkArgPlaceholdersForOverload(Sema &S,
988 MultiExprArg Args,
989 UnbridgedCastsSet &unbridged) {
990 for (unsigned i = 0, e = Args.size(); i != e; ++i)
991 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
992 return true;
993
994 return false;
995}
996
997/// Determine whether the given New declaration is an overload of the
998/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
999/// New and Old cannot be overloaded, e.g., if New has the same signature as
1000/// some function in Old (C++ 1.3.10) or if the Old declarations aren't
1001/// functions (or function templates) at all. When it does return Ovl_Match or
1002/// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
1003/// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
1004/// declaration.
1005///
1006/// Example: Given the following input:
1007///
1008/// void f(int, float); // #1
1009/// void f(int, int); // #2
1010/// int f(int, int); // #3
1011///
1012/// When we process #1, there is no previous declaration of "f", so IsOverload
1013/// will not be used.
1014///
1015/// When we process #2, Old contains only the FunctionDecl for #1. By comparing
1016/// the parameter types, we see that #1 and #2 are overloaded (since they have
1017/// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
1018/// unchanged.
1019///
1020/// When we process #3, Old is an overload set containing #1 and #2. We compare
1021/// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
1022/// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
1023/// functions are not part of the signature), IsOverload returns Ovl_Match and
1024/// MatchedDecl will be set to point to the FunctionDecl for #2.
1025///
1026/// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
1027/// by a using declaration. The rules for whether to hide shadow declarations
1028/// ignore some properties which otherwise figure into a function template's
1029/// signature.
1030Sema::OverloadKind
1031Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
1032 NamedDecl *&Match, bool NewIsUsingDecl) {
1033 for (LookupResult::iterator I = Old.begin(), E = Old.end();
1034 I != E; ++I) {
1035 NamedDecl *OldD = *I;
1036
1037 bool OldIsUsingDecl = false;
1038 if (isa<UsingShadowDecl>(OldD)) {
1039 OldIsUsingDecl = true;
1040
1041 // We can always introduce two using declarations into the same
1042 // context, even if they have identical signatures.
1043 if (NewIsUsingDecl) continue;
1044
1045 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
1046 }
1047
1048 // A using-declaration does not conflict with another declaration
1049 // if one of them is hidden.
1050 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
1051 continue;
1052
1053 // If either declaration was introduced by a using declaration,
1054 // we'll need to use slightly different rules for matching.
1055 // Essentially, these rules are the normal rules, except that
1056 // function templates hide function templates with different
1057 // return types or template parameter lists.
1058 bool UseMemberUsingDeclRules =
1059 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
1060 !New->getFriendObjectKind();
1061
1062 if (FunctionDecl *OldF = OldD->getAsFunction()) {
1063 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
1064 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
1065 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1066 continue;
1067 }
1068
1069 if (!isa<FunctionTemplateDecl>(OldD) &&
1070 !shouldLinkPossiblyHiddenDecl(*I, New))
1071 continue;
1072
1073 Match = *I;
1074 return Ovl_Match;
1075 }
1076
1077 // Builtins that have custom typechecking or have a reference should
1078 // not be overloadable or redeclarable.
1079 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1080 Match = *I;
1081 return Ovl_NonFunction;
1082 }
1083 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1084 // We can overload with these, which can show up when doing
1085 // redeclaration checks for UsingDecls.
1086 assert(Old.getLookupKind() == LookupUsingDeclName);
1087 } else if (isa<TagDecl>(OldD)) {
1088 // We can always overload with tags by hiding them.
1089 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1090 // Optimistically assume that an unresolved using decl will
1091 // overload; if it doesn't, we'll have to diagnose during
1092 // template instantiation.
1093 //
1094 // Exception: if the scope is dependent and this is not a class
1095 // member, the using declaration can only introduce an enumerator.
1096 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1097 Match = *I;
1098 return Ovl_NonFunction;
1099 }
1100 } else {
1101 // (C++ 13p1):
1102 // Only function declarations can be overloaded; object and type
1103 // declarations cannot be overloaded.
1104 Match = *I;
1105 return Ovl_NonFunction;
1106 }
1107 }
1108
1109 // C++ [temp.friend]p1:
1110 // For a friend function declaration that is not a template declaration:
1111 // -- if the name of the friend is a qualified or unqualified template-id,
1112 // [...], otherwise
1113 // -- if the name of the friend is a qualified-id and a matching
1114 // non-template function is found in the specified class or namespace,
1115 // the friend declaration refers to that function, otherwise,
1116 // -- if the name of the friend is a qualified-id and a matching function
1117 // template is found in the specified class or namespace, the friend
1118 // declaration refers to the deduced specialization of that function
1119 // template, otherwise
1120 // -- the name shall be an unqualified-id [...]
1121 // If we get here for a qualified friend declaration, we've just reached the
1122 // third bullet. If the type of the friend is dependent, skip this lookup
1123 // until instantiation.
1124 if (New->getFriendObjectKind() && New->getQualifier() &&
1125 !New->getDescribedFunctionTemplate() &&
1126 !New->getDependentSpecializationInfo() &&
1127 !New->getType()->isDependentType()) {
1128 LookupResult TemplateSpecResult(LookupResult::Temporary, Old);
1129 TemplateSpecResult.addAllDecls(Old);
1130 if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult,
1131 /*QualifiedFriend*/true)) {
1132 New->setInvalidDecl();
1133 return Ovl_Overload;
1134 }
1135
1136 Match = TemplateSpecResult.getAsSingle<FunctionDecl>();
1137 return Ovl_Match;
1138 }
1139
1140 return Ovl_Overload;
1141}
1142
1143bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1144 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs,
1145 bool ConsiderRequiresClauses) {
1146 // C++ [basic.start.main]p2: This function shall not be overloaded.
1147 if (New->isMain())
1148 return false;
1149
1150 // MSVCRT user defined entry points cannot be overloaded.
1151 if (New->isMSVCRTEntryPoint())
1152 return false;
1153
1154 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1155 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1156
1157 // C++ [temp.fct]p2:
1158 // A function template can be overloaded with other function templates
1159 // and with normal (non-template) functions.
1160 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1161 return true;
1162
1163 // Is the function New an overload of the function Old?
1164 QualType OldQType = Context.getCanonicalType(Old->getType());
1165 QualType NewQType = Context.getCanonicalType(New->getType());
1166
1167 // Compare the signatures (C++ 1.3.10) of the two functions to
1168 // determine whether they are overloads. If we find any mismatch
1169 // in the signature, they are overloads.
1170
1171 // If either of these functions is a K&R-style function (no
1172 // prototype), then we consider them to have matching signatures.
1173 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1174 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1175 return false;
1176
1177 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1178 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1179
1180 // The signature of a function includes the types of its
1181 // parameters (C++ 1.3.10), which includes the presence or absence
1182 // of the ellipsis; see C++ DR 357).
1183 if (OldQType != NewQType &&
1184 (OldType->getNumParams() != NewType->getNumParams() ||
1185 OldType->isVariadic() != NewType->isVariadic() ||
1186 !FunctionParamTypesAreEqual(OldType, NewType)))
1187 return true;
1188
1189 // C++ [temp.over.link]p4:
1190 // The signature of a function template consists of its function
1191 // signature, its return type and its template parameter list. The names
1192 // of the template parameters are significant only for establishing the
1193 // relationship between the template parameters and the rest of the
1194 // signature.
1195 //
1196 // We check the return type and template parameter lists for function
1197 // templates first; the remaining checks follow.
1198 //
1199 // However, we don't consider either of these when deciding whether
1200 // a member introduced by a shadow declaration is hidden.
1201 if (!UseMemberUsingDeclRules && NewTemplate &&
1202 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1203 OldTemplate->getTemplateParameters(),
1204 false, TPL_TemplateMatch) ||
1205 !Context.hasSameType(Old->getDeclaredReturnType(),
1206 New->getDeclaredReturnType())))
1207 return true;
1208
1209 // If the function is a class member, its signature includes the
1210 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1211 //
1212 // As part of this, also check whether one of the member functions
1213 // is static, in which case they are not overloads (C++
1214 // 13.1p2). While not part of the definition of the signature,
1215 // this check is important to determine whether these functions
1216 // can be overloaded.
1217 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1218 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1219 if (OldMethod && NewMethod &&
1220 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1221 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1222 if (!UseMemberUsingDeclRules &&
1223 (OldMethod->getRefQualifier() == RQ_None ||
1224 NewMethod->getRefQualifier() == RQ_None)) {
1225 // C++0x [over.load]p2:
1226 // - Member function declarations with the same name and the same
1227 // parameter-type-list as well as member function template
1228 // declarations with the same name, the same parameter-type-list, and
1229 // the same template parameter lists cannot be overloaded if any of
1230 // them, but not all, have a ref-qualifier (8.3.5).
1231 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1232 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1233 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1234 }
1235 return true;
1236 }
1237
1238 // We may not have applied the implicit const for a constexpr member
1239 // function yet (because we haven't yet resolved whether this is a static
1240 // or non-static member function). Add it now, on the assumption that this
1241 // is a redeclaration of OldMethod.
1242 auto OldQuals = OldMethod->getMethodQualifiers();
1243 auto NewQuals = NewMethod->getMethodQualifiers();
1244 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1245 !isa<CXXConstructorDecl>(NewMethod))
1246 NewQuals.addConst();
1247 // We do not allow overloading based off of '__restrict'.
1248 OldQuals.removeRestrict();
1249 NewQuals.removeRestrict();
1250 if (OldQuals != NewQuals)
1251 return true;
1252 }
1253
1254 // Though pass_object_size is placed on parameters and takes an argument, we
1255 // consider it to be a function-level modifier for the sake of function
1256 // identity. Either the function has one or more parameters with
1257 // pass_object_size or it doesn't.
1258 if (functionHasPassObjectSizeParams(New) !=
1259 functionHasPassObjectSizeParams(Old))
1260 return true;
1261
1262 // enable_if attributes are an order-sensitive part of the signature.
1263 for (specific_attr_iterator<EnableIfAttr>
1264 NewI = New->specific_attr_begin<EnableIfAttr>(),
1265 NewE = New->specific_attr_end<EnableIfAttr>(),
1266 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1267 OldE = Old->specific_attr_end<EnableIfAttr>();
1268 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1269 if (NewI == NewE || OldI == OldE)
1270 return true;
1271 llvm::FoldingSetNodeID NewID, OldID;
1272 NewI->getCond()->Profile(NewID, Context, true);
1273 OldI->getCond()->Profile(OldID, Context, true);
1274 if (NewID != OldID)
1275 return true;
1276 }
1277
1278 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1279 // Don't allow overloading of destructors. (In theory we could, but it
1280 // would be a giant change to clang.)
1281 if (!isa<CXXDestructorDecl>(New)) {
1282 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1283 OldTarget = IdentifyCUDATarget(Old);
1284 if (NewTarget != CFT_InvalidTarget) {
1285 assert((OldTarget != CFT_InvalidTarget) &&
1286 "Unexpected invalid target.");
1287
1288 // Allow overloading of functions with same signature and different CUDA
1289 // target attributes.
1290 if (NewTarget != OldTarget)
1291 return true;
1292 }
1293 }
1294 }
1295
1296 if (ConsiderRequiresClauses) {
1297 Expr *NewRC = New->getTrailingRequiresClause(),
1298 *OldRC = Old->getTrailingRequiresClause();
1299 if ((NewRC != nullptr) != (OldRC != nullptr))
1300 // RC are most certainly different - these are overloads.
1301 return true;
1302
1303 if (NewRC) {
1304 llvm::FoldingSetNodeID NewID, OldID;
1305 NewRC->Profile(NewID, Context, /*Canonical=*/true);
1306 OldRC->Profile(OldID, Context, /*Canonical=*/true);
1307 if (NewID != OldID)
1308 // RCs are not equivalent - these are overloads.
1309 return true;
1310 }
1311 }
1312
1313 // The signatures match; this is not an overload.
1314 return false;
1315}
1316
1317/// Tries a user-defined conversion from From to ToType.
1318///
1319/// Produces an implicit conversion sequence for when a standard conversion
1320/// is not an option. See TryImplicitConversion for more information.
1321static ImplicitConversionSequence
1322TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1323 bool SuppressUserConversions,
1324 AllowedExplicit AllowExplicit,
1325 bool InOverloadResolution,
1326 bool CStyle,
1327 bool AllowObjCWritebackConversion,
1328 bool AllowObjCConversionOnExplicit) {
1329 ImplicitConversionSequence ICS;
1330
1331 if (SuppressUserConversions) {
1332 // We're not in the case above, so there is no conversion that
1333 // we can perform.
1334 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1335 return ICS;
1336 }
1337
1338 // Attempt user-defined conversion.
1339 OverloadCandidateSet Conversions(From->getExprLoc(),
1340 OverloadCandidateSet::CSK_Normal);
1341 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1342 Conversions, AllowExplicit,
1343 AllowObjCConversionOnExplicit)) {
1344 case OR_Success:
1345 case OR_Deleted:
1346 ICS.setUserDefined();
1347 // C++ [over.ics.user]p4:
1348 // A conversion of an expression of class type to the same class
1349 // type is given Exact Match rank, and a conversion of an
1350 // expression of class type to a base class of that type is
1351 // given Conversion rank, in spite of the fact that a copy
1352 // constructor (i.e., a user-defined conversion function) is
1353 // called for those cases.
1354 if (CXXConstructorDecl *Constructor
1355 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1356 QualType FromCanon
1357 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1358 QualType ToCanon
1359 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1360 if (Constructor->isCopyConstructor() &&
1361 (FromCanon == ToCanon ||
1362 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1363 // Turn this into a "standard" conversion sequence, so that it
1364 // gets ranked with standard conversion sequences.
1365 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1366 ICS.setStandard();
1367 ICS.Standard.setAsIdentityConversion();
1368 ICS.Standard.setFromType(From->getType());
1369 ICS.Standard.setAllToTypes(ToType);
1370 ICS.Standard.CopyConstructor = Constructor;
1371 ICS.Standard.FoundCopyConstructor = Found;
1372 if (ToCanon != FromCanon)
1373 ICS.Standard.Second = ICK_Derived_To_Base;
1374 }
1375 }
1376 break;
1377
1378 case OR_Ambiguous:
1379 ICS.setAmbiguous();
1380 ICS.Ambiguous.setFromType(From->getType());
1381 ICS.Ambiguous.setToType(ToType);
1382 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1383 Cand != Conversions.end(); ++Cand)
1384 if (Cand->Best)
1385 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1386 break;
1387
1388 // Fall through.
1389 case OR_No_Viable_Function:
1390 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1391 break;
1392 }
1393
1394 return ICS;
1395}
1396
1397/// TryImplicitConversion - Attempt to perform an implicit conversion
1398/// from the given expression (Expr) to the given type (ToType). This
1399/// function returns an implicit conversion sequence that can be used
1400/// to perform the initialization. Given
1401///
1402/// void f(float f);
1403/// void g(int i) { f(i); }
1404///
1405/// this routine would produce an implicit conversion sequence to
1406/// describe the initialization of f from i, which will be a standard
1407/// conversion sequence containing an lvalue-to-rvalue conversion (C++
1408/// 4.1) followed by a floating-integral conversion (C++ 4.9).
1409//
1410/// Note that this routine only determines how the conversion can be
1411/// performed; it does not actually perform the conversion. As such,
1412/// it will not produce any diagnostics if no conversion is available,
1413/// but will instead return an implicit conversion sequence of kind
1414/// "BadConversion".
1415///
1416/// If @p SuppressUserConversions, then user-defined conversions are
1417/// not permitted.
1418/// If @p AllowExplicit, then explicit user-defined conversions are
1419/// permitted.
1420///
1421/// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1422/// writeback conversion, which allows __autoreleasing id* parameters to
1423/// be initialized with __strong id* or __weak id* arguments.
1424static ImplicitConversionSequence
1425TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1426 bool SuppressUserConversions,
1427 AllowedExplicit AllowExplicit,
1428 bool InOverloadResolution,
1429 bool CStyle,
1430 bool AllowObjCWritebackConversion,
1431 bool AllowObjCConversionOnExplicit) {
1432 ImplicitConversionSequence ICS;
1433 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1434 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1435 ICS.setStandard();
1436 return ICS;
1437 }
1438
1439 if (!S.getLangOpts().CPlusPlus) {
1440 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1441 return ICS;
1442 }
1443
1444 // C++ [over.ics.user]p4:
1445 // A conversion of an expression of class type to the same class
1446 // type is given Exact Match rank, and a conversion of an
1447 // expression of class type to a base class of that type is
1448 // given Conversion rank, in spite of the fact that a copy/move
1449 // constructor (i.e., a user-defined conversion function) is
1450 // called for those cases.
1451 QualType FromType = From->getType();
1452 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1453 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1454 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1455 ICS.setStandard();
1456 ICS.Standard.setAsIdentityConversion();
1457 ICS.Standard.setFromType(FromType);
1458 ICS.Standard.setAllToTypes(ToType);
1459
1460 // We don't actually check at this point whether there is a valid
1461 // copy/move constructor, since overloading just assumes that it
1462 // exists. When we actually perform initialization, we'll find the
1463 // appropriate constructor to copy the returned object, if needed.
1464 ICS.Standard.CopyConstructor = nullptr;
1465
1466 // Determine whether this is considered a derived-to-base conversion.
1467 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1468 ICS.Standard.Second = ICK_Derived_To_Base;
1469
1470 return ICS;
1471 }
1472
1473 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1474 AllowExplicit, InOverloadResolution, CStyle,
1475 AllowObjCWritebackConversion,
1476 AllowObjCConversionOnExplicit);
1477}
1478
1479ImplicitConversionSequence
1480Sema::TryImplicitConversion(Expr *From, QualType ToType,
1481 bool SuppressUserConversions,
1482 AllowedExplicit AllowExplicit,
1483 bool InOverloadResolution,
1484 bool CStyle,
1485 bool AllowObjCWritebackConversion) {
1486 return ::TryImplicitConversion(*this, From, ToType, SuppressUserConversions,
1487 AllowExplicit, InOverloadResolution, CStyle,
1488 AllowObjCWritebackConversion,
1489 /*AllowObjCConversionOnExplicit=*/false);
1490}
1491
1492/// PerformImplicitConversion - Perform an implicit conversion of the
1493/// expression From to the type ToType. Returns the
1494/// converted expression. Flavor is the kind of conversion we're
1495/// performing, used in the error message. If @p AllowExplicit,
1496/// explicit user-defined conversions are permitted.
1497ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1498 AssignmentAction Action,
1499 bool AllowExplicit) {
1500 if (checkPlaceholderForOverload(*this, From))
1501 return ExprError();
1502
1503 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1504 bool AllowObjCWritebackConversion
1505 = getLangOpts().ObjCAutoRefCount &&
1506 (Action == AA_Passing || Action == AA_Sending);
1507 if (getLangOpts().ObjC)
1508 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1509 From->getType(), From);
1510 ImplicitConversionSequence ICS = ::TryImplicitConversion(
1511 *this, From, ToType,
1512 /*SuppressUserConversions=*/false,
1513 AllowExplicit ? AllowedExplicit::All : AllowedExplicit::None,
1514 /*InOverloadResolution=*/false,
1515 /*CStyle=*/false, AllowObjCWritebackConversion,
1516 /*AllowObjCConversionOnExplicit=*/false);
1517 return PerformImplicitConversion(From, ToType, ICS, Action);
1518}
1519
1520/// Determine whether the conversion from FromType to ToType is a valid
1521/// conversion that strips "noexcept" or "noreturn" off the nested function
1522/// type.
1523bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1524 QualType &ResultTy) {
1525 if (Context.hasSameUnqualifiedType(FromType, ToType))
1526 return false;
1527
1528 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1529 // or F(t noexcept) -> F(t)
1530 // where F adds one of the following at most once:
1531 // - a pointer
1532 // - a member pointer
1533 // - a block pointer
1534 // Changes here need matching changes in FindCompositePointerType.
1535 CanQualType CanTo = Context.getCanonicalType(ToType);
1536 CanQualType CanFrom = Context.getCanonicalType(FromType);
1537 Type::TypeClass TyClass = CanTo->getTypeClass();
1538 if (TyClass != CanFrom->getTypeClass()) return false;
1539 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1540 if (TyClass == Type::Pointer) {
1541 CanTo = CanTo.castAs<PointerType>()->getPointeeType();
1542 CanFrom = CanFrom.castAs<PointerType>()->getPointeeType();
1543 } else if (TyClass == Type::BlockPointer) {
1544 CanTo = CanTo.castAs<BlockPointerType>()->getPointeeType();
1545 CanFrom = CanFrom.castAs<BlockPointerType>()->getPointeeType();
1546 } else if (TyClass == Type::MemberPointer) {
1547 auto ToMPT = CanTo.castAs<MemberPointerType>();
1548 auto FromMPT = CanFrom.castAs<MemberPointerType>();
1549 // A function pointer conversion cannot change the class of the function.
1550 if (ToMPT->getClass() != FromMPT->getClass())
1551 return false;
1552 CanTo = ToMPT->getPointeeType();
1553 CanFrom = FromMPT->getPointeeType();
1554 } else {
1555 return false;
1556 }
1557
1558 TyClass = CanTo->getTypeClass();
1559 if (TyClass != CanFrom->getTypeClass()) return false;
1560 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1561 return false;
1562 }
1563
1564 const auto *FromFn = cast<FunctionType>(CanFrom);
1565 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1566
1567 const auto *ToFn = cast<FunctionType>(CanTo);
1568 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1569
1570 bool Changed = false;
1571
1572 // Drop 'noreturn' if not present in target type.
1573 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1574 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1575 Changed = true;
1576 }
1577
1578 // Drop 'noexcept' if not present in target type.
1579 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1580 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1581 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1582 FromFn = cast<FunctionType>(
1583 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1584 EST_None)
1585 .getTypePtr());
1586 Changed = true;
1587 }
1588
1589 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1590 // only if the ExtParameterInfo lists of the two function prototypes can be
1591 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1592 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1593 bool CanUseToFPT, CanUseFromFPT;
1594 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1595 CanUseFromFPT, NewParamInfos) &&
1596 CanUseToFPT && !CanUseFromFPT) {
1597 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1598 ExtInfo.ExtParameterInfos =
1599 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1600 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1601 FromFPT->getParamTypes(), ExtInfo);
1602 FromFn = QT->getAs<FunctionType>();
1603 Changed = true;
1604 }
1605 }
1606
1607 if (!Changed)
1608 return false;
1609
1610 assert(QualType(FromFn, 0).isCanonical());
1611 if (QualType(FromFn, 0) != CanTo) return false;
1612
1613 ResultTy = ToType;
1614 return true;
1615}
1616
1617/// Determine whether the conversion from FromType to ToType is a valid
1618/// vector conversion.
1619///
1620/// \param ICK Will be set to the vector conversion kind, if this is a vector
1621/// conversion.
1622static bool IsVectorConversion(Sema &S, QualType FromType,
1623 QualType ToType, ImplicitConversionKind &ICK) {
1624 // We need at least one of these types to be a vector type to have a vector
1625 // conversion.
1626 if (!ToType->isVectorType() && !FromType->isVectorType())
1627 return false;
1628
1629 // Identical types require no conversions.
1630 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1631 return false;
1632
1633 // There are no conversions between extended vector types, only identity.
1634 if (ToType->isExtVectorType()) {
1635 // There are no conversions between extended vector types other than the
1636 // identity conversion.
1637 if (FromType->isExtVectorType())
1638 return false;
1639
1640 // Vector splat from any arithmetic type to a vector.
1641 if (FromType->isArithmeticType()) {
1642 ICK = ICK_Vector_Splat;
1643 return true;
1644 }
1645 }
1646
1647 if (ToType->isSizelessBuiltinType() || FromType->isSizelessBuiltinType())
1648 if (S.Context.areCompatibleSveTypes(FromType, ToType) ||
1649 S.Context.areLaxCompatibleSveTypes(FromType, ToType)) {
1650 ICK = ICK_SVE_Vector_Conversion;
1651 return true;
1652 }
1653
1654 // We can perform the conversion between vector types in the following cases:
1655 // 1)vector types are equivalent AltiVec and GCC vector types
1656 // 2)lax vector conversions are permitted and the vector types are of the
1657 // same size
1658 // 3)the destination type does not have the ARM MVE strict-polymorphism
1659 // attribute, which inhibits lax vector conversion for overload resolution
1660 // only
1661 if (ToType->isVectorType() && FromType->isVectorType()) {
1662 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1663 (S.isLaxVectorConversion(FromType, ToType) &&
1664 !ToType->hasAttr(attr::ArmMveStrictPolymorphism))) {
1665 ICK = ICK_Vector_Conversion;
1666 return true;
1667 }
1668 }
1669
1670 return false;
1671}
1672
1673static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1674 bool InOverloadResolution,
1675 StandardConversionSequence &SCS,
1676 bool CStyle);
1677
1678/// IsStandardConversion - Determines whether there is a standard
1679/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1680/// expression From to the type ToType. Standard conversion sequences
1681/// only consider non-class types; for conversions that involve class
1682/// types, use TryImplicitConversion. If a conversion exists, SCS will
1683/// contain the standard conversion sequence required to perform this
1684/// conversion and this routine will return true. Otherwise, this
1685/// routine will return false and the value of SCS is unspecified.
1686static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1687 bool InOverloadResolution,
1688 StandardConversionSequence &SCS,
1689 bool CStyle,
1690 bool AllowObjCWritebackConversion) {
1691 QualType FromType = From->getType();
1692
1693 // Standard conversions (C++ [conv])
1694 SCS.setAsIdentityConversion();
1695 SCS.IncompatibleObjC = false;
1696 SCS.setFromType(FromType);
1697 SCS.CopyConstructor = nullptr;
1698
1699 // There are no standard conversions for class types in C++, so
1700 // abort early. When overloading in C, however, we do permit them.
1701 if (S.getLangOpts().CPlusPlus &&
1702 (FromType->isRecordType() || ToType->isRecordType()))
1703 return false;
1704
1705 // The first conversion can be an lvalue-to-rvalue conversion,
1706 // array-to-pointer conversion, or function-to-pointer conversion
1707 // (C++ 4p1).
1708
1709 if (FromType == S.Context.OverloadTy) {
1710 DeclAccessPair AccessPair;
1711 if (FunctionDecl *Fn
1712 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1713 AccessPair)) {
1714 // We were able to resolve the address of the overloaded function,
1715 // so we can convert to the type of that function.
1716 FromType = Fn->getType();
1717 SCS.setFromType(FromType);
1718
1719 // we can sometimes resolve &foo<int> regardless of ToType, so check
1720 // if the type matches (identity) or we are converting to bool
1721 if (!S.Context.hasSameUnqualifiedType(
1722 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1723 QualType resultTy;
1724 // if the function type matches except for [[noreturn]], it's ok
1725 if (!S.IsFunctionConversion(FromType,
1726 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1727 // otherwise, only a boolean conversion is standard
1728 if (!ToType->isBooleanType())
1729 return false;
1730 }
1731
1732 // Check if the "from" expression is taking the address of an overloaded
1733 // function and recompute the FromType accordingly. Take advantage of the
1734 // fact that non-static member functions *must* have such an address-of
1735 // expression.
1736 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1737 if (Method && !Method->isStatic()) {
1738 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1739 "Non-unary operator on non-static member address");
1740 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1741 == UO_AddrOf &&
1742 "Non-address-of operator on non-static member address");
1743 const Type *ClassType
1744 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1745 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1746 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1747 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1748 UO_AddrOf &&
1749 "Non-address-of operator for overloaded function expression");
1750 FromType = S.Context.getPointerType(FromType);
1751 }
1752
1753 // Check that we've computed the proper type after overload resolution.
1754 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1755 // be calling it from within an NDEBUG block.
1756 assert(S.Context.hasSameType(
1757 FromType,
1758 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1759 } else {
1760 return false;
1761 }
1762 }
1763 // Lvalue-to-rvalue conversion (C++11 4.1):
1764 // A glvalue (3.10) of a non-function, non-array type T can
1765 // be converted to a prvalue.
1766 bool argIsLValue = From->isGLValue();
1767 if (argIsLValue &&
1768 !FromType->isFunctionType() && !FromType->isArrayType() &&
1769 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1770 SCS.First = ICK_Lvalue_To_Rvalue;
1771
1772 // C11 6.3.2.1p2:
1773 // ... if the lvalue has atomic type, the value has the non-atomic version
1774 // of the type of the lvalue ...
1775 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1776 FromType = Atomic->getValueType();
1777
1778 // If T is a non-class type, the type of the rvalue is the
1779 // cv-unqualified version of T. Otherwise, the type of the rvalue
1780 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1781 // just strip the qualifiers because they don't matter.
1782 FromType = FromType.getUnqualifiedType();
1783 } else if (FromType->isArrayType()) {
1784 // Array-to-pointer conversion (C++ 4.2)
1785 SCS.First = ICK_Array_To_Pointer;
1786
1787 // An lvalue or rvalue of type "array of N T" or "array of unknown
1788 // bound of T" can be converted to an rvalue of type "pointer to
1789 // T" (C++ 4.2p1).
1790 FromType = S.Context.getArrayDecayedType(FromType);
1791
1792 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1793 // This conversion is deprecated in C++03 (D.4)
1794 SCS.DeprecatedStringLiteralToCharPtr = true;
1795
1796 // For the purpose of ranking in overload resolution
1797 // (13.3.3.1.1), this conversion is considered an
1798 // array-to-pointer conversion followed by a qualification
1799 // conversion (4.4). (C++ 4.2p2)
1800 SCS.Second = ICK_Identity;
1801 SCS.Third = ICK_Qualification;
1802 SCS.QualificationIncludesObjCLifetime = false;
1803 SCS.setAllToTypes(FromType);
1804 return true;
1805 }
1806 } else if (FromType->isFunctionType() && argIsLValue) {
1807 // Function-to-pointer conversion (C++ 4.3).
1808 SCS.First = ICK_Function_To_Pointer;
1809
1810 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1811 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1812 if (!S.checkAddressOfFunctionIsAvailable(FD))
1813 return false;
1814
1815 // An lvalue of function type T can be converted to an rvalue of
1816 // type "pointer to T." The result is a pointer to the
1817 // function. (C++ 4.3p1).
1818 FromType = S.Context.getPointerType(FromType);
1819 } else {
1820 // We don't require any conversions for the first step.
1821 SCS.First = ICK_Identity;
1822 }
1823 SCS.setToType(0, FromType);
1824
1825 // The second conversion can be an integral promotion, floating
1826 // point promotion, integral conversion, floating point conversion,
1827 // floating-integral conversion, pointer conversion,
1828 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1829 // For overloading in C, this can also be a "compatible-type"
1830 // conversion.
1831 bool IncompatibleObjC = false;
1832 ImplicitConversionKind SecondICK = ICK_Identity;
1833 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1834 // The unqualified versions of the types are the same: there's no
1835 // conversion to do.
1836 SCS.Second = ICK_Identity;
1837 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1838 // Integral promotion (C++ 4.5).
1839 SCS.Second = ICK_Integral_Promotion;
1840 FromType = ToType.getUnqualifiedType();
1841 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1842 // Floating point promotion (C++ 4.6).
1843 SCS.Second = ICK_Floating_Promotion;
1844 FromType = ToType.getUnqualifiedType();
1845 } else if (S.IsComplexPromotion(FromType, ToType)) {
1846 // Complex promotion (Clang extension)
1847 SCS.Second = ICK_Complex_Promotion;
1848 FromType = ToType.getUnqualifiedType();
1849 } else if (ToType->isBooleanType() &&
1850 (FromType->isArithmeticType() ||
1851 FromType->isAnyPointerType() ||
1852 FromType->isBlockPointerType() ||
1853 FromType->isMemberPointerType())) {
1854 // Boolean conversions (C++ 4.12).
1855 SCS.Second = ICK_Boolean_Conversion;
1856 FromType = S.Context.BoolTy;
1857 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1858 ToType->isIntegralType(S.Context)) {
1859 // Integral conversions (C++ 4.7).
1860 SCS.Second = ICK_Integral_Conversion;
1861 FromType = ToType.getUnqualifiedType();
1862 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1863 // Complex conversions (C99 6.3.1.6)
1864 SCS.Second = ICK_Complex_Conversion;
1865 FromType = ToType.getUnqualifiedType();
1866 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1867 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1868 // Complex-real conversions (C99 6.3.1.7)
1869 SCS.Second = ICK_Complex_Real;
1870 FromType = ToType.getUnqualifiedType();
1871 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1872 // FIXME: disable conversions between long double and __float128 if
1873 // their representation is different until there is back end support
1874 // We of course allow this conversion if long double is really double.
1875
1876 // Conversions between bfloat and other floats are not permitted.
1877 if (FromType == S.Context.BFloat16Ty || ToType == S.Context.BFloat16Ty)
1878 return false;
1879 if (&S.Context.getFloatTypeSemantics(FromType) !=
1880 &S.Context.getFloatTypeSemantics(ToType)) {
1881 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1882 ToType == S.Context.LongDoubleTy) ||
1883 (FromType == S.Context.LongDoubleTy &&
1884 ToType == S.Context.Float128Ty));
1885 if (Float128AndLongDouble &&
1886 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1887 &llvm::APFloat::PPCDoubleDouble()))
1888 return false;
1889 }
1890 // Floating point conversions (C++ 4.8).
1891 SCS.Second = ICK_Floating_Conversion;
1892 FromType = ToType.getUnqualifiedType();
1893 } else if ((FromType->isRealFloatingType() &&
1894 ToType->isIntegralType(S.Context)) ||
1895 (FromType->isIntegralOrUnscopedEnumerationType() &&
1896 ToType->isRealFloatingType())) {
1897 // Conversions between bfloat and int are not permitted.
1898 if (FromType->isBFloat16Type() || ToType->isBFloat16Type())
1899 return false;
1900
1901 // Floating-integral conversions (C++ 4.9).
1902 SCS.Second = ICK_Floating_Integral;
1903 FromType = ToType.getUnqualifiedType();
1904 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1905 SCS.Second = ICK_Block_Pointer_Conversion;
1906 } else if (AllowObjCWritebackConversion &&
1907 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1908 SCS.Second = ICK_Writeback_Conversion;
1909 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1910 FromType, IncompatibleObjC)) {
1911 // Pointer conversions (C++ 4.10).
1912 SCS.Second = ICK_Pointer_Conversion;
1913 SCS.IncompatibleObjC = IncompatibleObjC;
1914 FromType = FromType.getUnqualifiedType();
1915 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1916 InOverloadResolution, FromType)) {
1917 // Pointer to member conversions (4.11).
1918 SCS.Second = ICK_Pointer_Member;
1919 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1920 SCS.Second = SecondICK;
1921 FromType = ToType.getUnqualifiedType();
1922 } else if (!S.getLangOpts().CPlusPlus &&
1923 S.Context.typesAreCompatible(ToType, FromType)) {
1924 // Compatible conversions (Clang extension for C function overloading)
1925 SCS.Second = ICK_Compatible_Conversion;
1926 FromType = ToType.getUnqualifiedType();
1927 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1928 InOverloadResolution,
1929 SCS, CStyle)) {
1930 SCS.Second = ICK_TransparentUnionConversion;
1931 FromType = ToType;
1932 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1933 CStyle)) {
1934 // tryAtomicConversion has updated the standard conversion sequence
1935 // appropriately.
1936 return true;
1937 } else if (ToType->isEventT() &&
1938 From->isIntegerConstantExpr(S.getASTContext()) &&
1939 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1940 SCS.Second = ICK_Zero_Event_Conversion;
1941 FromType = ToType;
1942 } else if (ToType->isQueueT() &&
1943 From->isIntegerConstantExpr(S.getASTContext()) &&
1944 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1945 SCS.Second = ICK_Zero_Queue_Conversion;
1946 FromType = ToType;
1947 } else if (ToType->isSamplerT() &&
1948 From->isIntegerConstantExpr(S.getASTContext())) {
1949 SCS.Second = ICK_Compatible_Conversion;
1950 FromType = ToType;
1951 } else {
1952 // No second conversion required.
1953 SCS.Second = ICK_Identity;
1954 }
1955 SCS.setToType(1, FromType);
1956
1957 // The third conversion can be a function pointer conversion or a
1958 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1959 bool ObjCLifetimeConversion;
1960 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1961 // Function pointer conversions (removing 'noexcept') including removal of
1962 // 'noreturn' (Clang extension).
1963 SCS.Third = ICK_Function_Conversion;
1964 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1965 ObjCLifetimeConversion)) {
1966 SCS.Third = ICK_Qualification;
1967 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1968 FromType = ToType;
1969 } else {
1970 // No conversion required
1971 SCS.Third = ICK_Identity;
1972 }
1973
1974 // C++ [over.best.ics]p6:
1975 // [...] Any difference in top-level cv-qualification is
1976 // subsumed by the initialization itself and does not constitute
1977 // a conversion. [...]
1978 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1979 QualType CanonTo = S.Context.getCanonicalType(ToType);
1980 if (CanonFrom.getLocalUnqualifiedType()
1981 == CanonTo.getLocalUnqualifiedType() &&
1982 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1983 FromType = ToType;
1984 CanonFrom = CanonTo;
1985 }
1986
1987 SCS.setToType(2, FromType);
1988
1989 if (CanonFrom == CanonTo)
1990 return true;
1991
1992 // If we have not converted the argument type to the parameter type,
1993 // this is a bad conversion sequence, unless we're resolving an overload in C.
1994 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1995 return false;
1996
1997 ExprResult ER = ExprResult{From};
1998 Sema::AssignConvertType Conv =
1999 S.CheckSingleAssignmentConstraints(ToType, ER,
2000 /*Diagnose=*/false,
2001 /*DiagnoseCFAudited=*/false,
2002 /*ConvertRHS=*/false);
2003 ImplicitConversionKind SecondConv;
2004 switch (Conv) {
2005 case Sema::Compatible:
2006 SecondConv = ICK_C_Only_Conversion;
2007 break;
2008 // For our purposes, discarding qualifiers is just as bad as using an
2009 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
2010 // qualifiers, as well.
2011 case Sema::CompatiblePointerDiscardsQualifiers:
2012 case Sema::IncompatiblePointer:
2013 case Sema::IncompatiblePointerSign:
2014 SecondConv = ICK_Incompatible_Pointer_Conversion;
2015 break;
2016 default:
2017 return false;
2018 }
2019
2020 // First can only be an lvalue conversion, so we pretend that this was the
2021 // second conversion. First should already be valid from earlier in the
2022 // function.
2023 SCS.Second = SecondConv;
2024 SCS.setToType(1, ToType);
2025
2026 // Third is Identity, because Second should rank us worse than any other
2027 // conversion. This could also be ICK_Qualification, but it's simpler to just
2028 // lump everything in with the second conversion, and we don't gain anything
2029 // from making this ICK_Qualification.
2030 SCS.Third = ICK_Identity;
2031 SCS.setToType(2, ToType);
2032 return true;
2033}
2034
2035static bool
2036IsTransparentUnionStandardConversion(Sema &S, Expr* From,
2037 QualType &ToType,
2038 bool InOverloadResolution,
2039 StandardConversionSequence &SCS,
2040 bool CStyle) {
2041
2042 const RecordType *UT = ToType->getAsUnionType();
2043 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
2044 return false;
2045 // The field to initialize within the transparent union.
2046 RecordDecl *UD = UT->getDecl();
2047 // It's compatible if the expression matches any of the fields.
2048 for (const auto *it : UD->fields()) {
2049 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
2050 CStyle, /*AllowObjCWritebackConversion=*/false)) {
2051 ToType = it->getType();
2052 return true;
2053 }
2054 }
2055 return false;
2056}
2057
2058/// IsIntegralPromotion - Determines whether the conversion from the
2059/// expression From (whose potentially-adjusted type is FromType) to
2060/// ToType is an integral promotion (C++ 4.5). If so, returns true and
2061/// sets PromotedType to the promoted type.
2062bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
2063 const BuiltinType *To = ToType->getAs<BuiltinType>();
2064 // All integers are built-in.
2065 if (!To) {
2066 return false;
2067 }
2068
2069 // An rvalue of type char, signed char, unsigned char, short int, or
2070 // unsigned short int can be converted to an rvalue of type int if
2071 // int can represent all the values of the source type; otherwise,
2072 // the source rvalue can be converted to an rvalue of type unsigned
2073 // int (C++ 4.5p1).
2074 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
2075 !FromType->isEnumeralType()) {
2076 if (// We can promote any signed, promotable integer type to an int
2077 (FromType->isSignedIntegerType() ||
2078 // We can promote any unsigned integer type whose size is
2079 // less than int to an int.
2080 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
2081 return To->getKind() == BuiltinType::Int;
2082 }
2083
2084 return To->getKind() == BuiltinType::UInt;
2085 }
2086
2087 // C++11 [conv.prom]p3:
2088 // A prvalue of an unscoped enumeration type whose underlying type is not
2089 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
2090 // following types that can represent all the values of the enumeration
2091 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
2092 // unsigned int, long int, unsigned long int, long long int, or unsigned
2093 // long long int. If none of the types in that list can represent all the
2094 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
2095 // type can be converted to an rvalue a prvalue of the extended integer type
2096 // with lowest integer conversion rank (4.13) greater than the rank of long
2097 // long in which all the values of the enumeration can be represented. If
2098 // there are two such extended types, the signed one is chosen.
2099 // C++11 [conv.prom]p4:
2100 // A prvalue of an unscoped enumeration type whose underlying type is fixed
2101 // can be converted to a prvalue of its underlying type. Moreover, if
2102 // integral promotion can be applied to its underlying type, a prvalue of an
2103 // unscoped enumeration type whose underlying type is fixed can also be
2104 // converted to a prvalue of the promoted underlying type.
2105 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
2106 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2107 // provided for a scoped enumeration.
2108 if (FromEnumType->getDecl()->isScoped())
2109 return false;
2110
2111 // We can perform an integral promotion to the underlying type of the enum,
2112 // even if that's not the promoted type. Note that the check for promoting
2113 // the underlying type is based on the type alone, and does not consider
2114 // the bitfield-ness of the actual source expression.
2115 if (FromEnumType->getDecl()->isFixed()) {
2116 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2117 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2118 IsIntegralPromotion(nullptr, Underlying, ToType);
2119 }
2120
2121 // We have already pre-calculated the promotion type, so this is trivial.
2122 if (ToType->isIntegerType() &&
2123 isCompleteType(From->getBeginLoc(), FromType))
2124 return Context.hasSameUnqualifiedType(
2125 ToType, FromEnumType->getDecl()->getPromotionType());
2126
2127 // C++ [conv.prom]p5:
2128 // If the bit-field has an enumerated type, it is treated as any other
2129 // value of that type for promotion purposes.
2130 //
2131 // ... so do not fall through into the bit-field checks below in C++.
2132 if (getLangOpts().CPlusPlus)
2133 return false;
2134 }
2135
2136 // C++0x [conv.prom]p2:
2137 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2138 // to an rvalue a prvalue of the first of the following types that can
2139 // represent all the values of its underlying type: int, unsigned int,
2140 // long int, unsigned long int, long long int, or unsigned long long int.
2141 // If none of the types in that list can represent all the values of its
2142 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2143 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2144 // type.
2145 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2146 ToType->isIntegerType()) {
2147 // Determine whether the type we're converting from is signed or
2148 // unsigned.
2149 bool FromIsSigned = FromType->isSignedIntegerType();
2150 uint64_t FromSize = Context.getTypeSize(FromType);
2151
2152 // The types we'll try to promote to, in the appropriate
2153 // order. Try each of these types.
2154 QualType PromoteTypes[6] = {
2155 Context.IntTy, Context.UnsignedIntTy,
2156 Context.LongTy, Context.UnsignedLongTy ,
2157 Context.LongLongTy, Context.UnsignedLongLongTy
2158 };
2159 for (int Idx = 0; Idx < 6; ++Idx) {
2160 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2161 if (FromSize < ToSize ||
2162 (FromSize == ToSize &&
2163 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2164 // We found the type that we can promote to. If this is the
2165 // type we wanted, we have a promotion. Otherwise, no
2166 // promotion.
2167 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2168 }
2169 }
2170 }
2171
2172 // An rvalue for an integral bit-field (9.6) can be converted to an
2173 // rvalue of type int if int can represent all the values of the
2174 // bit-field; otherwise, it can be converted to unsigned int if
2175 // unsigned int can represent all the values of the bit-field. If
2176 // the bit-field is larger yet, no integral promotion applies to
2177 // it. If the bit-field has an enumerated type, it is treated as any
2178 // other value of that type for promotion purposes (C++ 4.5p3).
2179 // FIXME: We should delay checking of bit-fields until we actually perform the
2180 // conversion.
2181 //
2182 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2183 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2184 // bit-fields and those whose underlying type is larger than int) for GCC
2185 // compatibility.
2186 if (From) {
2187 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2188 Optional<llvm::APSInt> BitWidth;
2189 if (FromType->isIntegralType(Context) &&
2190 (BitWidth =
2191 MemberDecl->getBitWidth()->getIntegerConstantExpr(Context))) {
2192 llvm::APSInt ToSize(BitWidth->getBitWidth(), BitWidth->isUnsigned());
2193 ToSize = Context.getTypeSize(ToType);
2194
2195 // Are we promoting to an int from a bitfield that fits in an int?
2196 if (*BitWidth < ToSize ||
2197 (FromType->isSignedIntegerType() && *BitWidth <= ToSize)) {
2198 return To->getKind() == BuiltinType::Int;
2199 }
2200
2201 // Are we promoting to an unsigned int from an unsigned bitfield
2202 // that fits into an unsigned int?
2203 if (FromType->isUnsignedIntegerType() && *BitWidth <= ToSize) {
2204 return To->getKind() == BuiltinType::UInt;
2205 }
2206
2207 return false;
2208 }
2209 }
2210 }
2211
2212 // An rvalue of type bool can be converted to an rvalue of type int,
2213 // with false becoming zero and true becoming one (C++ 4.5p4).
2214 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2215 return true;
2216 }
2217
2218 return false;
2219}
2220
2221/// IsFloatingPointPromotion - Determines whether the conversion from
2222/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2223/// returns true and sets PromotedType to the promoted type.
2224bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2225 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2226 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2227 /// An rvalue of type float can be converted to an rvalue of type
2228 /// double. (C++ 4.6p1).
2229 if (FromBuiltin->getKind() == BuiltinType::Float &&
2230 ToBuiltin->getKind() == BuiltinType::Double)
2231 return true;
2232
2233 // C99 6.3.1.5p1:
2234 // When a float is promoted to double or long double, or a
2235 // double is promoted to long double [...].
2236 if (!getLangOpts().CPlusPlus &&
2237 (FromBuiltin->getKind() == BuiltinType::Float ||
2238 FromBuiltin->getKind() == BuiltinType::Double) &&
2239 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2240 ToBuiltin->getKind() == BuiltinType::Float128))
2241 return true;
2242
2243 // Half can be promoted to float.
2244 if (!getLangOpts().NativeHalfType &&
2245 FromBuiltin->getKind() == BuiltinType::Half &&
2246 ToBuiltin->getKind() == BuiltinType::Float)
2247 return true;
2248 }
2249
2250 return false;
2251}
2252
2253/// Determine if a conversion is a complex promotion.
2254///
2255/// A complex promotion is defined as a complex -> complex conversion
2256/// where the conversion between the underlying real types is a
2257/// floating-point or integral promotion.
2258bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2259 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2260 if (!FromComplex)
2261 return false;
2262
2263 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2264 if (!ToComplex)
2265 return false;
2266
2267 return IsFloatingPointPromotion(FromComplex->getElementType(),
2268 ToComplex->getElementType()) ||
2269 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2270 ToComplex->getElementType());
2271}
2272
2273/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2274/// the pointer type FromPtr to a pointer to type ToPointee, with the
2275/// same type qualifiers as FromPtr has on its pointee type. ToType,
2276/// if non-empty, will be a pointer to ToType that may or may not have
2277/// the right set of qualifiers on its pointee.
2278///
2279static QualType
2280BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2281 QualType ToPointee, QualType ToType,
2282 ASTContext &Context,
2283 bool StripObjCLifetime = false) {
2284 assert((FromPtr->getTypeClass() == Type::Pointer ||
2285 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2286 "Invalid similarly-qualified pointer type");
2287
2288 /// Conversions to 'id' subsume cv-qualifier conversions.
2289 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2290 return ToType.getUnqualifiedType();
2291
2292 QualType CanonFromPointee
2293 = Context.getCanonicalType(FromPtr->getPointeeType());
2294 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2295 Qualifiers Quals = CanonFromPointee.getQualifiers();
2296
2297 if (StripObjCLifetime)
2298 Quals.removeObjCLifetime();
2299
2300 // Exact qualifier match -> return the pointer type we're converting to.
2301 if (CanonToPointee.getLocalQualifiers() == Quals) {
2302 // ToType is exactly what we need. Return it.
2303 if (!ToType.isNull())
2304 return ToType.getUnqualifiedType();
2305
2306 // Build a pointer to ToPointee. It has the right qualifiers
2307 // already.
2308 if (isa<ObjCObjectPointerType>(ToType))
2309 return Context.getObjCObjectPointerType(ToPointee);
2310 return Context.getPointerType(ToPointee);
2311 }
2312
2313 // Just build a canonical type that has the right qualifiers.
2314 QualType QualifiedCanonToPointee
2315 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2316
2317 if (isa<ObjCObjectPointerType>(ToType))
2318 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2319 return Context.getPointerType(QualifiedCanonToPointee);
2320}
2321
2322static bool isNullPointerConstantForConversion(Expr *Expr,
2323 bool InOverloadResolution,
2324 ASTContext &Context) {
2325 // Handle value-dependent integral null pointer constants correctly.
2326 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2327 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2328 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2329 return !InOverloadResolution;
2330
2331 return Expr->isNullPointerConstant(Context,
2332 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2333 : Expr::NPC_ValueDependentIsNull);
2334}
2335
2336/// IsPointerConversion - Determines whether the conversion of the
2337/// expression From, which has the (possibly adjusted) type FromType,
2338/// can be converted to the type ToType via a pointer conversion (C++
2339/// 4.10). If so, returns true and places the converted type (that
2340/// might differ from ToType in its cv-qualifiers at some level) into
2341/// ConvertedType.
2342///
2343/// This routine also supports conversions to and from block pointers
2344/// and conversions with Objective-C's 'id', 'id<protocols...>', and
2345/// pointers to interfaces. FIXME: Once we've determined the
2346/// appropriate overloading rules for Objective-C, we may want to
2347/// split the Objective-C checks into a different routine; however,
2348/// GCC seems to consider all of these conversions to be pointer
2349/// conversions, so for now they live here. IncompatibleObjC will be
2350/// set if the conversion is an allowed Objective-C conversion that
2351/// should result in a warning.
2352bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2353 bool InOverloadResolution,
2354 QualType& ConvertedType,
2355 bool &IncompatibleObjC) {
2356 IncompatibleObjC = false;
2357 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2358 IncompatibleObjC))
2359 return true;
2360
2361 // Conversion from a null pointer constant to any Objective-C pointer type.
2362 if (ToType->isObjCObjectPointerType() &&
2363 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2364 ConvertedType = ToType;
2365 return true;
2366 }
2367
2368 // Blocks: Block pointers can be converted to void*.
2369 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2370 ToType->castAs<PointerType>()->getPointeeType()->isVoidType()) {
2371 ConvertedType = ToType;
2372 return true;
2373 }
2374 // Blocks: A null pointer constant can be converted to a block
2375 // pointer type.
2376 if (ToType->isBlockPointerType() &&
2377 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2378 ConvertedType = ToType;
2379 return true;
2380 }
2381
2382 // If the left-hand-side is nullptr_t, the right side can be a null
2383 // pointer constant.
2384 if (ToType->isNullPtrType() &&
2385 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2386 ConvertedType = ToType;
2387 return true;
2388 }
2389
2390 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2391 if (!ToTypePtr)
2392 return false;
2393
2394 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2395 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2396 ConvertedType = ToType;
2397 return true;
2398 }
2399
2400 // Beyond this point, both types need to be pointers
2401 // , including objective-c pointers.
2402 QualType ToPointeeType = ToTypePtr->getPointeeType();
2403 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2404 !getLangOpts().ObjCAutoRefCount) {
2405 ConvertedType = BuildSimilarlyQualifiedPointerType(
2406 FromType->getAs<ObjCObjectPointerType>(),
2407 ToPointeeType,
2408 ToType, Context);
2409 return true;
2410 }
2411 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2412 if (!FromTypePtr)
2413 return false;
2414
2415 QualType FromPointeeType = FromTypePtr->getPointeeType();
2416
2417 // If the unqualified pointee types are the same, this can't be a
2418 // pointer conversion, so don't do all of the work below.
2419 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2420 return false;
2421
2422 // An rvalue of type "pointer to cv T," where T is an object type,
2423 // can be converted to an rvalue of type "pointer to cv void" (C++
2424 // 4.10p2).
2425 if (FromPointeeType->isIncompleteOrObjectType() &&
2426 ToPointeeType->isVoidType()) {
2427 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2428 ToPointeeType,
2429 ToType, Context,
2430 /*StripObjCLifetime=*/true);
2431 return true;
2432 }
2433
2434 // MSVC allows implicit function to void* type conversion.
2435 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2436 ToPointeeType->isVoidType()) {
2437 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2438 ToPointeeType,
2439 ToType, Context);
2440 return true;
2441 }
2442
2443 // When we're overloading in C, we allow a special kind of pointer
2444 // conversion for compatible-but-not-identical pointee types.
2445 if (!getLangOpts().CPlusPlus &&
2446 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2447 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2448 ToPointeeType,
2449 ToType, Context);
2450 return true;
2451 }
2452
2453 // C++ [conv.ptr]p3:
2454 //
2455 // An rvalue of type "pointer to cv D," where D is a class type,
2456 // can be converted to an rvalue of type "pointer to cv B," where
2457 // B is a base class (clause 10) of D. If B is an inaccessible
2458 // (clause 11) or ambiguous (10.2) base class of D, a program that
2459 // necessitates this conversion is ill-formed. The result of the
2460 // conversion is a pointer to the base class sub-object of the
2461 // derived class object. The null pointer value is converted to
2462 // the null pointer value of the destination type.
2463 //
2464 // Note that we do not check for ambiguity or inaccessibility
2465 // here. That is handled by CheckPointerConversion.
2466 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2467 ToPointeeType->isRecordType() &&
2468 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2469 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2470 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2471 ToPointeeType,
2472 ToType, Context);
2473 return true;
2474 }
2475
2476 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2477 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2478 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2479 ToPointeeType,
2480 ToType, Context);
2481 return true;
2482 }
2483
2484 return false;
2485}
2486
2487/// Adopt the given qualifiers for the given type.
2488static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2489 Qualifiers TQs = T.getQualifiers();
2490
2491 // Check whether qualifiers already match.
2492 if (TQs == Qs)
2493 return T;
2494
2495 if (Qs.compatiblyIncludes(TQs))
2496 return Context.getQualifiedType(T, Qs);
2497
2498 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2499}
2500
2501/// isObjCPointerConversion - Determines whether this is an
2502/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2503/// with the same arguments and return values.
2504bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2505 QualType& ConvertedType,
2506 bool &IncompatibleObjC) {
2507 if (!getLangOpts().ObjC)
2508 return false;
2509
2510 // The set of qualifiers on the type we're converting from.
2511 Qualifiers FromQualifiers = FromType.getQualifiers();
2512
2513 // First, we handle all conversions on ObjC object pointer types.
2514 const ObjCObjectPointerType* ToObjCPtr =
2515 ToType->getAs<ObjCObjectPointerType>();
2516 const ObjCObjectPointerType *FromObjCPtr =
2517 FromType->getAs<ObjCObjectPointerType>();
2518
2519 if (ToObjCPtr && FromObjCPtr) {
2520 // If the pointee types are the same (ignoring qualifications),
2521 // then this is not a pointer conversion.
2522 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2523 FromObjCPtr->getPointeeType()))
2524 return false;
2525
2526 // Conversion between Objective-C pointers.
2527 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2528 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2529 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2530 if (getLangOpts().CPlusPlus && LHS && RHS &&
2531 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2532 FromObjCPtr->getPointeeType()))
2533 return false;
2534 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2535 ToObjCPtr->getPointeeType(),
2536 ToType, Context);
2537 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2538 return true;
2539 }
2540
2541 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2542 // Okay: this is some kind of implicit downcast of Objective-C
2543 // interfaces, which is permitted. However, we're going to
2544 // complain about it.
2545 IncompatibleObjC = true;
2546 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2547 ToObjCPtr->getPointeeType(),
2548 ToType, Context);
2549 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2550 return true;
2551 }
2552 }
2553 // Beyond this point, both types need to be C pointers or block pointers.
2554 QualType ToPointeeType;
2555 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2556 ToPointeeType = ToCPtr->getPointeeType();
2557 else if (const BlockPointerType *ToBlockPtr =
2558 ToType->getAs<BlockPointerType>()) {
2559 // Objective C++: We're able to convert from a pointer to any object
2560 // to a block pointer type.
2561 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2562 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2563 return true;
2564 }
2565 ToPointeeType = ToBlockPtr->getPointeeType();
2566 }
2567 else if (FromType->getAs<BlockPointerType>() &&
2568 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2569 // Objective C++: We're able to convert from a block pointer type to a
2570 // pointer to any object.
2571 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2572 return true;
2573 }
2574 else
2575 return false;
2576
2577 QualType FromPointeeType;
2578 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2579 FromPointeeType = FromCPtr->getPointeeType();
2580 else if (const BlockPointerType *FromBlockPtr =
2581 FromType->getAs<BlockPointerType>())
2582 FromPointeeType = FromBlockPtr->getPointeeType();
2583 else
2584 return false;
2585
2586 // If we have pointers to pointers, recursively check whether this
2587 // is an Objective-C conversion.
2588 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2589 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2590 IncompatibleObjC)) {
2591 // We always complain about this conversion.
2592 IncompatibleObjC = true;
2593 ConvertedType = Context.getPointerType(ConvertedType);
2594 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2595 return true;
2596 }
2597 // Allow conversion of pointee being objective-c pointer to another one;
2598 // as in I* to id.
2599 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2600 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2601 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2602 IncompatibleObjC)) {
2603
2604 ConvertedType = Context.getPointerType(ConvertedType);
2605 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2606 return true;
2607 }
2608
2609 // If we have pointers to functions or blocks, check whether the only
2610 // differences in the argument and result types are in Objective-C
2611 // pointer conversions. If so, we permit the conversion (but
2612 // complain about it).
2613 const FunctionProtoType *FromFunctionType
2614 = FromPointeeType->getAs<FunctionProtoType>();
2615 const FunctionProtoType *ToFunctionType
2616 = ToPointeeType->getAs<FunctionProtoType>();
2617 if (FromFunctionType && ToFunctionType) {
2618 // If the function types are exactly the same, this isn't an
2619 // Objective-C pointer conversion.
2620 if (Context.getCanonicalType(FromPointeeType)
2621 == Context.getCanonicalType(ToPointeeType))
2622 return false;
2623
2624 // Perform the quick checks that will tell us whether these
2625 // function types are obviously different.
2626 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2627 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2628 FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals())
2629 return false;
2630
2631 bool HasObjCConversion = false;
2632 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2633 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2634 // Okay, the types match exactly. Nothing to do.
2635 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2636 ToFunctionType->getReturnType(),
2637 ConvertedType, IncompatibleObjC)) {
2638 // Okay, we have an Objective-C pointer conversion.
2639 HasObjCConversion = true;
2640 } else {
2641 // Function types are too different. Abort.
2642 return false;
2643 }
2644
2645 // Check argument types.
2646 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2647 ArgIdx != NumArgs; ++ArgIdx) {
2648 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2649 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2650 if (Context.getCanonicalType(FromArgType)
2651 == Context.getCanonicalType(ToArgType)) {
2652 // Okay, the types match exactly. Nothing to do.
2653 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2654 ConvertedType, IncompatibleObjC)) {
2655 // Okay, we have an Objective-C pointer conversion.
2656 HasObjCConversion = true;
2657 } else {
2658 // Argument types are too different. Abort.
2659 return false;
2660 }
2661 }
2662
2663 if (HasObjCConversion) {
2664 // We had an Objective-C conversion. Allow this pointer
2665 // conversion, but complain about it.
2666 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2667 IncompatibleObjC = true;
2668 return true;
2669 }
2670 }
2671
2672 return false;
2673}
2674
2675/// Determine whether this is an Objective-C writeback conversion,
2676/// used for parameter passing when performing automatic reference counting.
2677///
2678/// \param FromType The type we're converting form.
2679///
2680/// \param ToType The type we're converting to.
2681///
2682/// \param ConvertedType The type that will be produced after applying
2683/// this conversion.
2684bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2685 QualType &ConvertedType) {
2686 if (!getLangOpts().ObjCAutoRefCount ||
2687 Context.hasSameUnqualifiedType(FromType, ToType))
2688 return false;
2689
2690 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2691 QualType ToPointee;
2692 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2693 ToPointee = ToPointer->getPointeeType();
2694 else
2695 return false;
2696
2697 Qualifiers ToQuals = ToPointee.getQualifiers();
2698 if (!ToPointee->isObjCLifetimeType() ||
2699 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2700 !ToQuals.withoutObjCLifetime().empty())
2701 return false;
2702
2703 // Argument must be a pointer to __strong to __weak.
2704 QualType FromPointee;
2705 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2706 FromPointee = FromPointer->getPointeeType();
2707 else
2708 return false;
2709
2710 Qualifiers FromQuals = FromPointee.getQualifiers();
2711 if (!FromPointee->isObjCLifetimeType() ||
2712 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2713 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2714 return false;
2715
2716 // Make sure that we have compatible qualifiers.
2717 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2718 if (!ToQuals.compatiblyIncludes(FromQuals))
2719 return false;
2720
2721 // Remove qualifiers from the pointee type we're converting from; they
2722 // aren't used in the compatibility check belong, and we'll be adding back
2723 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2724 FromPointee = FromPointee.getUnqualifiedType();
2725
2726 // The unqualified form of the pointee types must be compatible.
2727 ToPointee = ToPointee.getUnqualifiedType();
2728 bool IncompatibleObjC;
2729 if (Context.typesAreCompatible(FromPointee, ToPointee))
2730 FromPointee = ToPointee;
2731 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2732 IncompatibleObjC))
2733 return false;
2734
2735 /// Construct the type we're converting to, which is a pointer to
2736 /// __autoreleasing pointee.
2737 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2738 ConvertedType = Context.getPointerType(FromPointee);
2739 return true;
2740}
2741
2742bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2743 QualType& ConvertedType) {
2744 QualType ToPointeeType;
2745 if (const BlockPointerType *ToBlockPtr =
2746 ToType->getAs<BlockPointerType>())
2747 ToPointeeType = ToBlockPtr->getPointeeType();
2748 else
2749 return false;
2750
2751 QualType FromPointeeType;
2752 if (const BlockPointerType *FromBlockPtr =
2753 FromType->getAs<BlockPointerType>())
2754 FromPointeeType = FromBlockPtr->getPointeeType();
2755 else
2756 return false;
2757 // We have pointer to blocks, check whether the only
2758 // differences in the argument and result types are in Objective-C
2759 // pointer conversions. If so, we permit the conversion.
2760
2761 const FunctionProtoType *FromFunctionType
2762 = FromPointeeType->getAs<FunctionProtoType>();
2763 const FunctionProtoType *ToFunctionType
2764 = ToPointeeType->getAs<FunctionProtoType>();
2765
2766 if (!FromFunctionType || !ToFunctionType)
2767 return false;
2768
2769 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2770 return true;
2771
2772 // Perform the quick checks that will tell us whether these
2773 // function types are obviously different.
2774 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2775 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2776 return false;
2777
2778 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2779 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2780 if (FromEInfo != ToEInfo)
2781 return false;
2782
2783 bool IncompatibleObjC = false;
2784 if (Context.hasSameType(FromFunctionType->getReturnType(),
2785 ToFunctionType->getReturnType())) {
2786 // Okay, the types match exactly. Nothing to do.
2787 } else {
2788 QualType RHS = FromFunctionType->getReturnType();
2789 QualType LHS = ToFunctionType->getReturnType();
2790 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2791 !RHS.hasQualifiers() && LHS.hasQualifiers())
2792 LHS = LHS.getUnqualifiedType();
2793
2794 if (Context.hasSameType(RHS,LHS)) {
2795 // OK exact match.
2796 } else if (isObjCPointerConversion(RHS, LHS,
2797 ConvertedType, IncompatibleObjC)) {
2798 if (IncompatibleObjC)
2799 return false;
2800 // Okay, we have an Objective-C pointer conversion.
2801 }
2802 else
2803 return false;
2804 }
2805
2806 // Check argument types.
2807 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2808 ArgIdx != NumArgs; ++ArgIdx) {
2809 IncompatibleObjC = false;
2810 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2811 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2812 if (Context.hasSameType(FromArgType, ToArgType)) {
2813 // Okay, the types match exactly. Nothing to do.
2814 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2815 ConvertedType, IncompatibleObjC)) {
2816 if (IncompatibleObjC)
2817 return false;
2818 // Okay, we have an Objective-C pointer conversion.
2819 } else
2820 // Argument types are too different. Abort.
2821 return false;
2822 }
2823
2824 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2825 bool CanUseToFPT, CanUseFromFPT;
2826 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2827 CanUseToFPT, CanUseFromFPT,
2828 NewParamInfos))
2829 return false;
2830
2831 ConvertedType = ToType;
2832 return true;
2833}
2834
2835enum {
2836 ft_default,
2837 ft_different_class,
2838 ft_parameter_arity,
2839 ft_parameter_mismatch,
2840 ft_return_type,
2841 ft_qualifer_mismatch,
2842 ft_noexcept
2843};
2844
2845/// Attempts to get the FunctionProtoType from a Type. Handles
2846/// MemberFunctionPointers properly.
2847static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2848 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2849 return FPT;
2850
2851 if (auto *MPT = FromType->getAs<MemberPointerType>())
2852 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2853
2854 return nullptr;
2855}
2856
2857/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2858/// function types. Catches different number of parameter, mismatch in
2859/// parameter types, and different return types.
2860void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2861 QualType FromType, QualType ToType) {
2862 // If either type is not valid, include no extra info.
2863 if (FromType.isNull() || ToType.isNull()) {
2864 PDiag << ft_default;
2865 return;
2866 }
2867
2868 // Get the function type from the pointers.
2869 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2870 const auto *FromMember = FromType->castAs<MemberPointerType>(),
2871 *ToMember = ToType->castAs<MemberPointerType>();
2872 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2873 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2874 << QualType(FromMember->getClass(), 0);
2875 return;
2876 }
2877 FromType = FromMember->getPointeeType();
2878 ToType = ToMember->getPointeeType();
2879 }
2880
2881 if (FromType->isPointerType())
2882 FromType = FromType->getPointeeType();
2883 if (ToType->isPointerType())
2884 ToType = ToType->getPointeeType();
2885
2886 // Remove references.
2887 FromType = FromType.getNonReferenceType();
2888 ToType = ToType.getNonReferenceType();
2889
2890 // Don't print extra info for non-specialized template functions.
2891 if (FromType->isInstantiationDependentType() &&
2892 !FromType->getAs<TemplateSpecializationType>()) {
2893 PDiag << ft_default;
2894 return;
2895 }
2896
2897 // No extra info for same types.
2898 if (Context.hasSameType(FromType, ToType)) {
2899 PDiag << ft_default;
2900 return;
2901 }
2902
2903 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2904 *ToFunction = tryGetFunctionProtoType(ToType);
2905
2906 // Both types need to be function types.
2907 if (!FromFunction || !ToFunction) {
2908 PDiag << ft_default;
2909 return;
2910 }
2911
2912 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2913 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2914 << FromFunction->getNumParams();
2915 return;
2916 }
2917
2918 // Handle different parameter types.
2919 unsigned ArgPos;
2920 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2921 PDiag << ft_parameter_mismatch << ArgPos + 1
2922 << ToFunction->getParamType(ArgPos)
2923 << FromFunction->getParamType(ArgPos);
2924 return;
2925 }
2926
2927 // Handle different return type.
2928 if (!Context.hasSameType(FromFunction->getReturnType(),
2929 ToFunction->getReturnType())) {
2930 PDiag << ft_return_type << ToFunction->getReturnType()
2931 << FromFunction->getReturnType();
2932 return;
2933 }
2934
2935 if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) {
2936 PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals()
2937 << FromFunction->getMethodQuals();
2938 return;
2939 }
2940
2941 // Handle exception specification differences on canonical type (in C++17
2942 // onwards).
2943 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2944 ->isNothrow() !=
2945 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2946 ->isNothrow()) {
2947 PDiag << ft_noexcept;
2948 return;
2949 }
2950
2951 // Unable to find a difference, so add no extra info.
2952 PDiag << ft_default;
2953}
2954
2955/// FunctionParamTypesAreEqual - This routine checks two function proto types
2956/// for equality of their argument types. Caller has already checked that
2957/// they have same number of arguments. If the parameters are different,
2958/// ArgPos will have the parameter index of the first different parameter.
2959bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2960 const FunctionProtoType *NewType,
2961 unsigned *ArgPos) {
2962 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2963 N = NewType->param_type_begin(),
2964 E = OldType->param_type_end();
2965 O && (O != E); ++O, ++N) {
2966 // Ignore address spaces in pointee type. This is to disallow overloading
2967 // on __ptr32/__ptr64 address spaces.
2968 QualType Old = Context.removePtrSizeAddrSpace(O->getUnqualifiedType());
2969 QualType New = Context.removePtrSizeAddrSpace(N->getUnqualifiedType());
2970
2971 if (!Context.hasSameType(Old, New)) {
2972 if (ArgPos)
2973 *ArgPos = O - OldType->param_type_begin();
2974 return false;
2975 }
2976 }
2977 return true;
2978}
2979
2980/// CheckPointerConversion - Check the pointer conversion from the
2981/// expression From to the type ToType. This routine checks for
2982/// ambiguous or inaccessible derived-to-base pointer
2983/// conversions for which IsPointerConversion has already returned
2984/// true. It returns true and produces a diagnostic if there was an
2985/// error, or returns false otherwise.
2986bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2987 CastKind &Kind,
2988 CXXCastPath& BasePath,
2989 bool IgnoreBaseAccess,
2990 bool Diagnose) {
2991 QualType FromType = From->getType();
2992 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2993
2994 Kind = CK_BitCast;
2995
2996 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2997 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2998 Expr::NPCK_ZeroExpression) {
2999 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
3000 DiagRuntimeBehavior(From->getExprLoc(), From,
3001 PDiag(diag::warn_impcast_bool_to_null_pointer)
3002 << ToType << From->getSourceRange());
3003 else if (!isUnevaluatedContext())
3004 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
3005 << ToType << From->getSourceRange();
3006 }
3007 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
3008 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
3009 QualType FromPointeeType = FromPtrType->getPointeeType(),
3010 ToPointeeType = ToPtrType->getPointeeType();
3011
3012 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
3013 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
3014 // We must have a derived-to-base conversion. Check an
3015 // ambiguous or inaccessible conversion.
3016 unsigned InaccessibleID = 0;
3017 unsigned AmbiguousID = 0;
3018 if (Diagnose) {
3019 InaccessibleID = diag::err_upcast_to_inaccessible_base;
3020 AmbiguousID = diag::err_ambiguous_derived_to_base_conv;
3021 }
3022 if (CheckDerivedToBaseConversion(
3023 FromPointeeType, ToPointeeType, InaccessibleID, AmbiguousID,
3024 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
3025 &BasePath, IgnoreBaseAccess))
3026 return true;
3027
3028 // The conversion was successful.
3029 Kind = CK_DerivedToBase;
3030 }
3031
3032 if (Diagnose && !IsCStyleOrFunctionalCast &&
3033 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
3034 assert(getLangOpts().MSVCCompat &&
3035 "this should only be possible with MSVCCompat!");
3036 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
3037 << From->getSourceRange();
3038 }
3039 }
3040 } else if (const ObjCObjectPointerType *ToPtrType =
3041 ToType->getAs<ObjCObjectPointerType>()) {
3042 if (const ObjCObjectPointerType *FromPtrType =
3043 FromType->getAs<ObjCObjectPointerType>()) {
3044 // Objective-C++ conversions are always okay.
3045 // FIXME: We should have a different class of conversions for the
3046 // Objective-C++ implicit conversions.
3047 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
3048 return false;
3049 } else if (FromType->isBlockPointerType()) {
3050 Kind = CK_BlockPointerToObjCPointerCast;
3051 } else {
3052 Kind = CK_CPointerToObjCPointerCast;
3053 }
3054 } else if (ToType->isBlockPointerType()) {
3055 if (!FromType->isBlockPointerType())
3056 Kind = CK_AnyPointerToBlockPointerCast;
3057 }
3058
3059 // We shouldn't fall into this case unless it's valid for other
3060 // reasons.
3061 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
3062 Kind = CK_NullToPointer;
3063
3064 return false;
3065}
3066
3067/// IsMemberPointerConversion - Determines whether the conversion of the
3068/// expression From, which has the (possibly adjusted) type FromType, can be
3069/// converted to the type ToType via a member pointer conversion (C++ 4.11).
3070/// If so, returns true and places the converted type (that might differ from
3071/// ToType in its cv-qualifiers at some level) into ConvertedType.
3072bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
3073 QualType ToType,
3074 bool InOverloadResolution,
3075 QualType &ConvertedType) {
3076 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
3077 if (!ToTypePtr)
3078 return false;
3079
3080 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
3081 if (From->isNullPointerConstant(Context,
3082 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
3083 : Expr::NPC_ValueDependentIsNull)) {
3084 ConvertedType = ToType;
3085 return true;
3086 }
3087
3088 // Otherwise, both types have to be member pointers.
3089 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
3090 if (!FromTypePtr)
3091 return false;
3092
3093 // A pointer to member of B can be converted to a pointer to member of D,
3094 // where D is derived from B (C++ 4.11p2).
3095 QualType FromClass(FromTypePtr->getClass(), 0);
3096 QualType ToClass(ToTypePtr->getClass(), 0);
3097
3098 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
3099 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
3100 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
3101 ToClass.getTypePtr());
3102 return true;
3103 }
3104
3105 return false;
3106}
3107
3108/// CheckMemberPointerConversion - Check the member pointer conversion from the
3109/// expression From to the type ToType. This routine checks for ambiguous or
3110/// virtual or inaccessible base-to-derived member pointer conversions
3111/// for which IsMemberPointerConversion has already returned true. It returns
3112/// true and produces a diagnostic if there was an error, or returns false
3113/// otherwise.
3114bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3115 CastKind &Kind,
3116 CXXCastPath &BasePath,
3117 bool IgnoreBaseAccess) {
3118 QualType FromType = From->getType();
3119 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3120 if (!FromPtrType) {
3121 // This must be a null pointer to member pointer conversion
3122 assert(From->isNullPointerConstant(Context,
3123 Expr::NPC_ValueDependentIsNull) &&
3124 "Expr must be null pointer constant!");
3125 Kind = CK_NullToMemberPointer;
3126 return false;
3127 }
3128
3129 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3130 assert(ToPtrType && "No member pointer cast has a target type "
3131 "that is not a member pointer.");
3132
3133 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3134 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3135
3136 // FIXME: What about dependent types?
3137 assert(FromClass->isRecordType() && "Pointer into non-class.");
3138 assert(ToClass->isRecordType() && "Pointer into non-class.");
3139
3140 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3141 /*DetectVirtual=*/true);
3142 bool DerivationOkay =
3143 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3144 assert(DerivationOkay &&
3145 "Should not have been called if derivation isn't OK.");
3146 (void)DerivationOkay;
3147
3148 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3149 getUnqualifiedType())) {
3150 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3151 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3152 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3153 return true;
3154 }
3155
3156 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3157 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3158 << FromClass << ToClass << QualType(VBase, 0)
3159 << From->getSourceRange();
3160 return true;
3161 }
3162
3163 if (!IgnoreBaseAccess)
3164 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3165 Paths.front(),
3166 diag::err_downcast_from_inaccessible_base);
3167
3168 // Must be a base to derived member conversion.
3169 BuildBasePathArray(Paths, BasePath);
3170 Kind = CK_BaseToDerivedMemberPointer;
3171 return false;
3172}
3173
3174/// Determine whether the lifetime conversion between the two given
3175/// qualifiers sets is nontrivial.
3176static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3177 Qualifiers ToQuals) {
3178 // Converting anything to const __unsafe_unretained is trivial.
3179 if (ToQuals.hasConst() &&
3180 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3181 return false;
3182
3183 return true;
3184}
3185
3186/// Perform a single iteration of the loop for checking if a qualification
3187/// conversion is valid.
3188///
3189/// Specifically, check whether any change between the qualifiers of \p
3190/// FromType and \p ToType is permissible, given knowledge about whether every
3191/// outer layer is const-qualified.
3192static bool isQualificationConversionStep(QualType FromType, QualType ToType,
3193 bool CStyle, bool IsTopLevel,
3194 bool &PreviousToQualsIncludeConst,
3195 bool &ObjCLifetimeConversion) {
3196 Qualifiers FromQuals = FromType.getQualifiers();
3197 Qualifiers ToQuals = ToType.getQualifiers();
3198
3199 // Ignore __unaligned qualifier if this type is void.
3200 if (ToType.getUnqualifiedType()->isVoidType())
3201 FromQuals.removeUnaligned();
3202
3203 // Objective-C ARC:
3204 // Check Objective-C lifetime conversions.
3205 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime()) {
3206 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3207 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3208 ObjCLifetimeConversion = true;
3209 FromQuals.removeObjCLifetime();
3210 ToQuals.removeObjCLifetime();
3211 } else {
3212 // Qualification conversions cannot cast between different
3213 // Objective-C lifetime qualifiers.
3214 return false;
3215 }
3216 }
3217
3218 // Allow addition/removal of GC attributes but not changing GC attributes.
3219 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3220 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3221 FromQuals.removeObjCGCAttr();
3222 ToQuals.removeObjCGCAttr();
3223 }
3224
3225 // -- for every j > 0, if const is in cv 1,j then const is in cv
3226 // 2,j, and similarly for volatile.
3227 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3228 return false;
3229
3230 // If address spaces mismatch:
3231 // - in top level it is only valid to convert to addr space that is a
3232 // superset in all cases apart from C-style casts where we allow
3233 // conversions between overlapping address spaces.
3234 // - in non-top levels it is not a valid conversion.
3235 if (ToQuals.getAddressSpace() != FromQuals.getAddressSpace() &&
3236 (!IsTopLevel ||
3237 !(ToQuals.isAddressSpaceSupersetOf(FromQuals) ||
3238 (CStyle && FromQuals.isAddressSpaceSupersetOf(ToQuals)))))
3239 return false;
3240
3241 // -- if the cv 1,j and cv 2,j are different, then const is in
3242 // every cv for 0 < k < j.
3243 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() &&
3244 !PreviousToQualsIncludeConst)
3245 return false;
3246
3247 // Keep track of whether all prior cv-qualifiers in the "to" type
3248 // include const.
3249 PreviousToQualsIncludeConst =
3250 PreviousToQualsIncludeConst && ToQuals.hasConst();
3251 return true;
3252}
3253
3254/// IsQualificationConversion - Determines whether the conversion from
3255/// an rvalue of type FromType to ToType is a qualification conversion
3256/// (C++ 4.4).
3257///
3258/// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3259/// when the qualification conversion involves a change in the Objective-C
3260/// object lifetime.
3261bool
3262Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3263 bool CStyle, bool &ObjCLifetimeConversion) {
3264 FromType = Context.getCanonicalType(FromType);
3265 ToType = Context.getCanonicalType(ToType);
3266 ObjCLifetimeConversion = false;
3267
3268 // If FromType and ToType are the same type, this is not a
3269 // qualification conversion.
3270 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3271 return false;
3272
3273 // (C++ 4.4p4):
3274 // A conversion can add cv-qualifiers at levels other than the first
3275 // in multi-level pointers, subject to the following rules: [...]
3276 bool PreviousToQualsIncludeConst = true;
3277 bool UnwrappedAnyPointer = false;
3278 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3279 if (!isQualificationConversionStep(
3280 FromType, ToType, CStyle, !UnwrappedAnyPointer,
3281 PreviousToQualsIncludeConst, ObjCLifetimeConversion))
3282 return false;
3283 UnwrappedAnyPointer = true;
3284 }
3285
3286 // We are left with FromType and ToType being the pointee types
3287 // after unwrapping the original FromType and ToType the same number
3288 // of times. If we unwrapped any pointers, and if FromType and
3289 // ToType have the same unqualified type (since we checked
3290 // qualifiers above), then this is a qualification conversion.
3291 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3292}
3293
3294/// - Determine whether this is a conversion from a scalar type to an
3295/// atomic type.
3296///
3297/// If successful, updates \c SCS's second and third steps in the conversion
3298/// sequence to finish the conversion.
3299static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3300 bool InOverloadResolution,
3301 StandardConversionSequence &SCS,
3302 bool CStyle) {
3303 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3304 if (!ToAtomic)
3305 return false;
3306
3307 StandardConversionSequence InnerSCS;
3308 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3309 InOverloadResolution, InnerSCS,
3310 CStyle, /*AllowObjCWritebackConversion=*/false))
3311 return false;
3312
3313 SCS.Second = InnerSCS.Second;
3314 SCS.setToType(1, InnerSCS.getToType(1));
3315 SCS.Third = InnerSCS.Third;
3316 SCS.QualificationIncludesObjCLifetime
3317 = InnerSCS.QualificationIncludesObjCLifetime;
3318 SCS.setToType(2, InnerSCS.getToType(2));
3319 return true;
3320}
3321
3322static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3323 CXXConstructorDecl *Constructor,
3324 QualType Type) {
3325 const auto *CtorType = Constructor->getType()->castAs<FunctionProtoType>();
3326 if (CtorType->getNumParams() > 0) {
3327 QualType FirstArg = CtorType->getParamType(0);
3328 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3329 return true;
3330 }
3331 return false;
3332}
3333
3334static OverloadingResult
3335IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3336 CXXRecordDecl *To,
3337 UserDefinedConversionSequence &User,
3338 OverloadCandidateSet &CandidateSet,
3339 bool AllowExplicit) {
3340 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3341 for (auto *D : S.LookupConstructors(To)) {
3342 auto Info = getConstructorInfo(D);
3343 if (!Info)
3344 continue;
3345
3346 bool Usable = !Info.Constructor->isInvalidDecl() &&
3347 S.isInitListConstructor(Info.Constructor);
3348 if (Usable) {
3349 // If the first argument is (a reference to) the target type,
3350 // suppress conversions.
3351 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3352 S.Context, Info.Constructor, ToType);
3353 if (Info.ConstructorTmpl)
3354 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3355 /*ExplicitArgs*/ nullptr, From,
3356 CandidateSet, SuppressUserConversions,
3357 /*PartialOverloading*/ false,
3358 AllowExplicit);
3359 else
3360 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3361 CandidateSet, SuppressUserConversions,
3362 /*PartialOverloading*/ false, AllowExplicit);
3363 }
3364 }
3365
3366 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3367
3368 OverloadCandidateSet::iterator Best;
3369 switch (auto Result =
3370 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3371 case OR_Deleted:
3372 case OR_Success: {
3373 // Record the standard conversion we used and the conversion function.
3374 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3375 QualType ThisType = Constructor->getThisType();
3376 // Initializer lists don't have conversions as such.
3377 User.Before.setAsIdentityConversion();
3378 User.HadMultipleCandidates = HadMultipleCandidates;
3379 User.ConversionFunction = Constructor;
3380 User.FoundConversionFunction = Best->FoundDecl;
3381 User.After.setAsIdentityConversion();
3382 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3383 User.After.setAllToTypes(ToType);
3384 return Result;
3385 }
3386
3387 case OR_No_Viable_Function:
3388 return OR_No_Viable_Function;
3389 case OR_Ambiguous:
3390 return OR_Ambiguous;
3391 }
3392
3393 llvm_unreachable("Invalid OverloadResult!");
3394}
3395
3396/// Determines whether there is a user-defined conversion sequence
3397/// (C++ [over.ics.user]) that converts expression From to the type
3398/// ToType. If such a conversion exists, User will contain the
3399/// user-defined conversion sequence that performs such a conversion
3400/// and this routine will return true. Otherwise, this routine returns
3401/// false and User is unspecified.
3402///
3403/// \param AllowExplicit true if the conversion should consider C++0x
3404/// "explicit" conversion functions as well as non-explicit conversion
3405/// functions (C++0x [class.conv.fct]p2).
3406///
3407/// \param AllowObjCConversionOnExplicit true if the conversion should
3408/// allow an extra Objective-C pointer conversion on uses of explicit
3409/// constructors. Requires \c AllowExplicit to also be set.
3410static OverloadingResult
3411IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3412 UserDefinedConversionSequence &User,
3413 OverloadCandidateSet &CandidateSet,
3414 AllowedExplicit AllowExplicit,
3415 bool AllowObjCConversionOnExplicit) {
3416 assert(AllowExplicit != AllowedExplicit::None ||
3417 !AllowObjCConversionOnExplicit);
3418 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3419
3420 // Whether we will only visit constructors.
3421 bool ConstructorsOnly = false;
3422
3423 // If the type we are conversion to is a class type, enumerate its
3424 // constructors.
3425 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3426 // C++ [over.match.ctor]p1:
3427 // When objects of class type are direct-initialized (8.5), or
3428 // copy-initialized from an expression of the same or a
3429 // derived class type (8.5), overload resolution selects the
3430 // constructor. [...] For copy-initialization, the candidate
3431 // functions are all the converting constructors (12.3.1) of
3432 // that class. The argument list is the expression-list within
3433 // the parentheses of the initializer.
3434 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3435 (From->getType()->getAs<RecordType>() &&
3436 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3437 ConstructorsOnly = true;
3438
3439 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3440 // We're not going to find any constructors.
3441 } else if (CXXRecordDecl *ToRecordDecl
3442 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3443
3444 Expr **Args = &From;
3445 unsigned NumArgs = 1;
3446 bool ListInitializing = false;
3447 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3448 // But first, see if there is an init-list-constructor that will work.
3449 OverloadingResult Result = IsInitializerListConstructorConversion(
3450 S, From, ToType, ToRecordDecl, User, CandidateSet,
3451 AllowExplicit == AllowedExplicit::All);
3452 if (Result != OR_No_Viable_Function)
3453 return Result;
3454 // Never mind.
3455 CandidateSet.clear(
3456 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3457
3458 // If we're list-initializing, we pass the individual elements as
3459 // arguments, not the entire list.
3460 Args = InitList->getInits();
3461 NumArgs = InitList->getNumInits();
3462 ListInitializing = true;
3463 }
3464
3465 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3466 auto Info = getConstructorInfo(D);
3467 if (!Info)
3468 continue;
3469
3470 bool Usable = !Info.Constructor->isInvalidDecl();
3471 if (!ListInitializing)
3472 Usable = Usable && Info.Constructor->isConvertingConstructor(
3473 /*AllowExplicit*/ true);
3474 if (Usable) {
3475 bool SuppressUserConversions = !ConstructorsOnly;
3476 if (SuppressUserConversions && ListInitializing) {
3477 SuppressUserConversions = false;
3478 if (NumArgs == 1) {
3479 // If the first argument is (a reference to) the target type,
3480 // suppress conversions.
3481 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3482 S.Context, Info.Constructor, ToType);
3483 }
3484 }
3485 if (Info.ConstructorTmpl)
3486 S.AddTemplateOverloadCandidate(
3487 Info.ConstructorTmpl, Info.FoundDecl,
3488 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3489 CandidateSet, SuppressUserConversions,
3490 /*PartialOverloading*/ false,
3491 AllowExplicit == AllowedExplicit::All);
3492 else
3493 // Allow one user-defined conversion when user specifies a
3494 // From->ToType conversion via an static cast (c-style, etc).
3495 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3496 llvm::makeArrayRef(Args, NumArgs),
3497 CandidateSet, SuppressUserConversions,
3498 /*PartialOverloading*/ false,
3499 AllowExplicit == AllowedExplicit::All);
3500 }
3501 }
3502 }
3503 }
3504
3505 // Enumerate conversion functions, if we're allowed to.
3506 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3507 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3508 // No conversion functions from incomplete types.
3509 } else if (const RecordType *FromRecordType =
3510 From->getType()->getAs<RecordType>()) {
3511 if (CXXRecordDecl *FromRecordDecl
3512 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3513 // Add all of the conversion functions as candidates.
3514 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3515 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3516 DeclAccessPair FoundDecl = I.getPair();
3517 NamedDecl *D = FoundDecl.getDecl();
3518 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3519 if (isa<UsingShadowDecl>(D))
3520 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3521
3522 CXXConversionDecl *Conv;
3523 FunctionTemplateDecl *ConvTemplate;
3524 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3525 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3526 else
3527 Conv = cast<CXXConversionDecl>(D);
3528
3529 if (ConvTemplate)
3530 S.AddTemplateConversionCandidate(
3531 ConvTemplate, FoundDecl, ActingContext, From, ToType,
3532 CandidateSet, AllowObjCConversionOnExplicit,
3533 AllowExplicit != AllowedExplicit::None);
3534 else
3535 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, ToType,
3536 CandidateSet, AllowObjCConversionOnExplicit,
3537 AllowExplicit != AllowedExplicit::None);
3538 }
3539 }
3540 }
3541
3542 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3543
3544 OverloadCandidateSet::iterator Best;
3545 switch (auto Result =
3546 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3547 case OR_Success:
3548 case OR_Deleted:
3549 // Record the standard conversion we used and the conversion function.
3550 if (CXXConstructorDecl *Constructor
3551 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3552 // C++ [over.ics.user]p1:
3553 // If the user-defined conversion is specified by a
3554 // constructor (12.3.1), the initial standard conversion
3555 // sequence converts the source type to the type required by
3556 // the argument of the constructor.
3557 //
3558 QualType ThisType = Constructor->getThisType();
3559 if (isa<InitListExpr>(From)) {
3560 // Initializer lists don't have conversions as such.
3561 User.Before.setAsIdentityConversion();
3562 } else {
3563 if (Best->Conversions[0].isEllipsis())
3564 User.EllipsisConversion = true;
3565 else {
3566 User.Before = Best->Conversions[0].Standard;
3567 User.EllipsisConversion = false;
3568 }
3569 }
3570 User.HadMultipleCandidates = HadMultipleCandidates;
3571 User.ConversionFunction = Constructor;
3572 User.FoundConversionFunction = Best->FoundDecl;
3573 User.After.setAsIdentityConversion();
3574 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3575 User.After.setAllToTypes(ToType);
3576 return Result;
3577 }
3578 if (CXXConversionDecl *Conversion
3579 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3580 // C++ [over.ics.user]p1:
3581 //
3582 // [...] If the user-defined conversion is specified by a
3583 // conversion function (12.3.2), the initial standard
3584 // conversion sequence converts the source type to the
3585 // implicit object parameter of the conversion function.
3586 User.Before = Best->Conversions[0].Standard;
3587 User.HadMultipleCandidates = HadMultipleCandidates;
3588 User.ConversionFunction = Conversion;
3589 User.FoundConversionFunction = Best->FoundDecl;
3590 User.EllipsisConversion = false;
3591
3592 // C++ [over.ics.user]p2:
3593 // The second standard conversion sequence converts the
3594 // result of the user-defined conversion to the target type
3595 // for the sequence. Since an implicit conversion sequence
3596 // is an initialization, the special rules for
3597 // initialization by user-defined conversion apply when
3598 // selecting the best user-defined conversion for a
3599 // user-defined conversion sequence (see 13.3.3 and
3600 // 13.3.3.1).
3601 User.After = Best->FinalConversion;
3602 return Result;
3603 }
3604 llvm_unreachable("Not a constructor or conversion function?");
3605
3606 case OR_No_Viable_Function:
3607 return OR_No_Viable_Function;
3608
3609 case OR_Ambiguous:
3610 return OR_Ambiguous;
3611 }
3612
3613 llvm_unreachable("Invalid OverloadResult!");
3614}
3615
3616bool
3617Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3618 ImplicitConversionSequence ICS;
3619 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3620 OverloadCandidateSet::CSK_Normal);
3621 OverloadingResult OvResult =
3622 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3623 CandidateSet, AllowedExplicit::None, false);
3624
3625 if (!(OvResult == OR_Ambiguous ||
3626 (OvResult == OR_No_Viable_Function && !CandidateSet.empty())))
3627 return false;
3628
3629 auto Cands = CandidateSet.CompleteCandidates(
3630 *this,
3631 OvResult == OR_Ambiguous ? OCD_AmbiguousCandidates : OCD_AllCandidates,
3632 From);
3633 if (OvResult == OR_Ambiguous)
3634 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3635 << From->getType() << ToType << From->getSourceRange();
3636 else { // OR_No_Viable_Function && !CandidateSet.empty()
3637 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3638 diag::err_typecheck_nonviable_condition_incomplete,
3639 From->getType(), From->getSourceRange()))
3640 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3641 << false << From->getType() << From->getSourceRange() << ToType;
3642 }
3643
3644 CandidateSet.NoteCandidates(
3645 *this, From, Cands);
3646 return true;
3647}
3648
3649// Helper for compareConversionFunctions that gets the FunctionType that the
3650// conversion-operator return value 'points' to, or nullptr.
3651static const FunctionType *
3652getConversionOpReturnTyAsFunction(CXXConversionDecl *Conv) {
3653 const FunctionType *ConvFuncTy = Conv->getType()->castAs<FunctionType>();
3654 const PointerType *RetPtrTy =
3655 ConvFuncTy->getReturnType()->getAs<PointerType>();
3656
3657 if (!RetPtrTy)
3658 return nullptr;
3659
3660 return RetPtrTy->getPointeeType()->getAs<FunctionType>();
3661}
3662
3663/// Compare the user-defined conversion functions or constructors
3664/// of two user-defined conversion sequences to determine whether any ordering
3665/// is possible.
3666static ImplicitConversionSequence::CompareKind
3667compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3668 FunctionDecl *Function2) {
3669 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3670 CXXConversionDecl *Conv2 = dyn_cast_or_null<CXXConversionDecl>(Function2);
3671 if (!Conv1 || !Conv2)
3672 return ImplicitConversionSequence::Indistinguishable;
3673
3674 if (!Conv1->getParent()->isLambda() || !Conv2->getParent()->isLambda())
3675 return ImplicitConversionSequence::Indistinguishable;
3676
3677 // Objective-C++:
3678 // If both conversion functions are implicitly-declared conversions from
3679 // a lambda closure type to a function pointer and a block pointer,
3680 // respectively, always prefer the conversion to a function pointer,
3681 // because the function pointer is more lightweight and is more likely
3682 // to keep code working.
3683 if (S.getLangOpts().ObjC && S.getLangOpts().CPlusPlus11) {
3684 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3685 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3686 if (Block1 != Block2)
3687 return Block1 ? ImplicitConversionSequence::Worse
3688 : ImplicitConversionSequence::Better;
3689 }
3690
3691 // In order to support multiple calling conventions for the lambda conversion
3692 // operator (such as when the free and member function calling convention is
3693 // different), prefer the 'free' mechanism, followed by the calling-convention
3694 // of operator(). The latter is in place to support the MSVC-like solution of
3695 // defining ALL of the possible conversions in regards to calling-convention.
3696 const FunctionType *Conv1FuncRet = getConversionOpReturnTyAsFunction(Conv1);
3697 const FunctionType *Conv2FuncRet = getConversionOpReturnTyAsFunction(Conv2);
3698
3699 if (Conv1FuncRet && Conv2FuncRet &&
3700 Conv1FuncRet->getCallConv() != Conv2FuncRet->getCallConv()) {
3701 CallingConv Conv1CC = Conv1FuncRet->getCallConv();
3702 CallingConv Conv2CC = Conv2FuncRet->getCallConv();
3703
3704 CXXMethodDecl *CallOp = Conv2->getParent()->getLambdaCallOperator();
3705 const FunctionProtoType *CallOpProto =
3706 CallOp->getType()->getAs<FunctionProtoType>();
3707
3708 CallingConv CallOpCC =
3709 CallOp->getType()->getAs<FunctionType>()->getCallConv();
3710 CallingConv DefaultFree = S.Context.getDefaultCallingConvention(
3711 CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
3712 CallingConv DefaultMember = S.Context.getDefaultCallingConvention(
3713 CallOpProto->isVariadic(), /*IsCXXMethod=*/true);
3714
3715 CallingConv PrefOrder[] = {DefaultFree, DefaultMember, CallOpCC};
3716 for (CallingConv CC : PrefOrder) {
3717 if (Conv1CC == CC)
3718 return ImplicitConversionSequence::Better;
3719 if (Conv2CC == CC)
3720 return ImplicitConversionSequence::Worse;
3721 }
3722 }
3723
3724 return ImplicitConversionSequence::Indistinguishable;
3725}
3726
3727static bool hasDeprecatedStringLiteralToCharPtrConversion(
3728 const ImplicitConversionSequence &ICS) {
3729 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3730 (ICS.isUserDefined() &&
3731 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3732}
3733
3734/// CompareImplicitConversionSequences - Compare two implicit
3735/// conversion sequences to determine whether one is better than the
3736/// other or if they are indistinguishable (C++ 13.3.3.2).
3737static ImplicitConversionSequence::CompareKind
3738CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3739 const ImplicitConversionSequence& ICS1,
3740 const ImplicitConversionSequence& ICS2)
3741{
3742 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3743 // conversion sequences (as defined in 13.3.3.1)
3744 // -- a standard conversion sequence (13.3.3.1.1) is a better
3745 // conversion sequence than a user-defined conversion sequence or
3746 // an ellipsis conversion sequence, and
3747 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3748 // conversion sequence than an ellipsis conversion sequence
3749 // (13.3.3.1.3).
3750 //
3751 // C++0x [over.best.ics]p10:
3752 // For the purpose of ranking implicit conversion sequences as
3753 // described in 13.3.3.2, the ambiguous conversion sequence is
3754 // treated as a user-defined sequence that is indistinguishable
3755 // from any other user-defined conversion sequence.
3756
3757 // String literal to 'char *' conversion has been deprecated in C++03. It has
3758 // been removed from C++11. We still accept this conversion, if it happens at
3759 // the best viable function. Otherwise, this conversion is considered worse
3760 // than ellipsis conversion. Consider this as an extension; this is not in the
3761 // standard. For example:
3762 //
3763 // int &f(...); // #1
3764 // void f(char*); // #2
3765 // void g() { int &r = f("foo"); }
3766 //
3767 // In C++03, we pick #2 as the best viable function.
3768 // In C++11, we pick #1 as the best viable function, because ellipsis
3769 // conversion is better than string-literal to char* conversion (since there
3770 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3771 // convert arguments, #2 would be the best viable function in C++11.
3772 // If the best viable function has this conversion, a warning will be issued
3773 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3774
3775 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3776 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3777 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3778 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3779 ? ImplicitConversionSequence::Worse
3780 : ImplicitConversionSequence::Better;
3781
3782 if (ICS1.getKindRank() < ICS2.getKindRank())
3783 return ImplicitConversionSequence::Better;
3784 if (ICS2.getKindRank() < ICS1.getKindRank())
3785 return ImplicitConversionSequence::Worse;
3786
3787 // The following checks require both conversion sequences to be of
3788 // the same kind.
3789 if (ICS1.getKind() != ICS2.getKind())
3790 return ImplicitConversionSequence::Indistinguishable;
3791
3792 ImplicitConversionSequence::CompareKind Result =
3793 ImplicitConversionSequence::Indistinguishable;
3794
3795 // Two implicit conversion sequences of the same form are
3796 // indistinguishable conversion sequences unless one of the
3797 // following rules apply: (C++ 13.3.3.2p3):
3798
3799 // List-initialization sequence L1 is a better conversion sequence than
3800 // list-initialization sequence L2 if:
3801 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3802 // if not that,
3803 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3804 // and N1 is smaller than N2.,
3805 // even if one of the other rules in this paragraph would otherwise apply.
3806 if (!ICS1.isBad()) {
3807 if (ICS1.isStdInitializerListElement() &&
3808 !ICS2.isStdInitializerListElement())
3809 return ImplicitConversionSequence::Better;
3810 if (!ICS1.isStdInitializerListElement() &&
3811 ICS2.isStdInitializerListElement())
3812 return ImplicitConversionSequence::Worse;
3813 }
3814
3815 if (ICS1.isStandard())
3816 // Standard conversion sequence S1 is a better conversion sequence than
3817 // standard conversion sequence S2 if [...]
3818 Result = CompareStandardConversionSequences(S, Loc,
3819 ICS1.Standard, ICS2.Standard);
3820 else if (ICS1.isUserDefined()) {
3821 // User-defined conversion sequence U1 is a better conversion
3822 // sequence than another user-defined conversion sequence U2 if
3823 // they contain the same user-defined conversion function or
3824 // constructor and if the second standard conversion sequence of
3825 // U1 is better than the second standard conversion sequence of
3826 // U2 (C++ 13.3.3.2p3).
3827 if (ICS1.UserDefined.ConversionFunction ==
3828 ICS2.UserDefined.ConversionFunction)
3829 Result = CompareStandardConversionSequences(S, Loc,
3830 ICS1.UserDefined.After,
3831 ICS2.UserDefined.After);
3832 else
3833 Result = compareConversionFunctions(S,
3834 ICS1.UserDefined.ConversionFunction,
3835 ICS2.UserDefined.ConversionFunction);
3836 }
3837
3838 return Result;
3839}
3840
3841// Per 13.3.3.2p3, compare the given standard conversion sequences to
3842// determine if one is a proper subset of the other.
3843static ImplicitConversionSequence::CompareKind
3844compareStandardConversionSubsets(ASTContext &Context,
3845 const StandardConversionSequence& SCS1,
3846 const StandardConversionSequence& SCS2) {
3847 ImplicitConversionSequence::CompareKind Result
3848 = ImplicitConversionSequence::Indistinguishable;
3849
3850 // the identity conversion sequence is considered to be a subsequence of
3851 // any non-identity conversion sequence
3852 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3853 return ImplicitConversionSequence::Better;
3854 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3855 return ImplicitConversionSequence::Worse;
3856
3857 if (SCS1.Second != SCS2.Second) {
3858 if (SCS1.Second == ICK_Identity)
3859 Result = ImplicitConversionSequence::Better;
3860 else if (SCS2.Second == ICK_Identity)
3861 Result = ImplicitConversionSequence::Worse;
3862 else
3863 return ImplicitConversionSequence::Indistinguishable;
3864 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3865 return ImplicitConversionSequence::Indistinguishable;
3866
3867 if (SCS1.Third == SCS2.Third) {
3868 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3869 : ImplicitConversionSequence::Indistinguishable;
3870 }
3871
3872 if (SCS1.Third == ICK_Identity)
3873 return Result == ImplicitConversionSequence::Worse
3874 ? ImplicitConversionSequence::Indistinguishable
3875 : ImplicitConversionSequence::Better;
3876
3877 if (SCS2.Third == ICK_Identity)
3878 return Result == ImplicitConversionSequence::Better
3879 ? ImplicitConversionSequence::Indistinguishable
3880 : ImplicitConversionSequence::Worse;
3881
3882 return ImplicitConversionSequence::Indistinguishable;
3883}
3884
3885/// Determine whether one of the given reference bindings is better
3886/// than the other based on what kind of bindings they are.
3887static bool
3888isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3889 const StandardConversionSequence &SCS2) {
3890 // C++0x [over.ics.rank]p3b4:
3891 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3892 // implicit object parameter of a non-static member function declared
3893 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3894 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3895 // lvalue reference to a function lvalue and S2 binds an rvalue
3896 // reference*.
3897 //
3898 // FIXME: Rvalue references. We're going rogue with the above edits,
3899 // because the semantics in the current C++0x working paper (N3225 at the
3900 // time of this writing) break the standard definition of std::forward
3901 // and std::reference_wrapper when dealing with references to functions.
3902 // Proposed wording changes submitted to CWG for consideration.
3903 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3904 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3905 return false;
3906
3907 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3908 SCS2.IsLvalueReference) ||
3909 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3910 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3911}
3912
3913enum class FixedEnumPromotion {
3914 None,
3915 ToUnderlyingType,
3916 ToPromotedUnderlyingType
3917};
3918
3919/// Returns kind of fixed enum promotion the \a SCS uses.
3920static FixedEnumPromotion
3921getFixedEnumPromtion(Sema &S, const StandardConversionSequence &SCS) {
3922
3923 if (SCS.Second != ICK_Integral_Promotion)
3924 return FixedEnumPromotion::None;
3925
3926 QualType FromType = SCS.getFromType();
3927 if (!FromType->isEnumeralType())
3928 return FixedEnumPromotion::None;
3929
3930 EnumDecl *Enum = FromType->getAs<EnumType>()->getDecl();
3931 if (!Enum->isFixed())
3932 return FixedEnumPromotion::None;
3933
3934 QualType UnderlyingType = Enum->getIntegerType();
3935 if (S.Context.hasSameType(SCS.getToType(1), UnderlyingType))
3936 return FixedEnumPromotion::ToUnderlyingType;
3937
3938 return FixedEnumPromotion::ToPromotedUnderlyingType;
3939}
3940
3941/// CompareStandardConversionSequences - Compare two standard
3942/// conversion sequences to determine whether one is better than the
3943/// other or if they are indistinguishable (C++ 13.3.3.2p3).
3944static ImplicitConversionSequence::CompareKind
3945CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3946 const StandardConversionSequence& SCS1,
3947 const StandardConversionSequence& SCS2)
3948{
3949 // Standard conversion sequence S1 is a better conversion sequence
3950 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3951
3952 // -- S1 is a proper subsequence of S2 (comparing the conversion
3953 // sequences in the canonical form defined by 13.3.3.1.1,
3954 // excluding any Lvalue Transformation; the identity conversion
3955 // sequence is considered to be a subsequence of any
3956 // non-identity conversion sequence) or, if not that,
3957 if (ImplicitConversionSequence::CompareKind CK
3958 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3959 return CK;
3960
3961 // -- the rank of S1 is better than the rank of S2 (by the rules
3962 // defined below), or, if not that,
3963 ImplicitConversionRank Rank1 = SCS1.getRank();
3964 ImplicitConversionRank Rank2 = SCS2.getRank();
3965 if (Rank1 < Rank2)
3966 return ImplicitConversionSequence::Better;
3967 else if (Rank2 < Rank1)
3968 return ImplicitConversionSequence::Worse;
3969
3970 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3971 // are indistinguishable unless one of the following rules
3972 // applies:
3973
3974 // A conversion that is not a conversion of a pointer, or
3975 // pointer to member, to bool is better than another conversion
3976 // that is such a conversion.
3977 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3978 return SCS2.isPointerConversionToBool()
3979 ? ImplicitConversionSequence::Better
3980 : ImplicitConversionSequence::Worse;
3981
3982 // C++14 [over.ics.rank]p4b2:
3983 // This is retroactively applied to C++11 by CWG 1601.
3984 //
3985 // A conversion that promotes an enumeration whose underlying type is fixed
3986 // to its underlying type is better than one that promotes to the promoted
3987 // underlying type, if the two are different.
3988 FixedEnumPromotion FEP1 = getFixedEnumPromtion(S, SCS1);
3989 FixedEnumPromotion FEP2 = getFixedEnumPromtion(S, SCS2);
3990 if (FEP1 != FixedEnumPromotion::None && FEP2 != FixedEnumPromotion::None &&
3991 FEP1 != FEP2)
3992 return FEP1 == FixedEnumPromotion::ToUnderlyingType
3993 ? ImplicitConversionSequence::Better
3994 : ImplicitConversionSequence::Worse;
3995
3996 // C++ [over.ics.rank]p4b2:
3997 //
3998 // If class B is derived directly or indirectly from class A,
3999 // conversion of B* to A* is better than conversion of B* to
4000 // void*, and conversion of A* to void* is better than conversion
4001 // of B* to void*.
4002 bool SCS1ConvertsToVoid
4003 = SCS1.isPointerConversionToVoidPointer(S.Context);
4004 bool SCS2ConvertsToVoid
4005 = SCS2.isPointerConversionToVoidPointer(S.Context);
4006 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
4007 // Exactly one of the conversion sequences is a conversion to
4008 // a void pointer; it's the worse conversion.
4009 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
4010 : ImplicitConversionSequence::Worse;
4011 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
4012 // Neither conversion sequence converts to a void pointer; compare
4013 // their derived-to-base conversions.
4014 if (ImplicitConversionSequence::CompareKind DerivedCK
4015 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
4016 return DerivedCK;
4017 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
4018 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
4019 // Both conversion sequences are conversions to void
4020 // pointers. Compare the source types to determine if there's an
4021 // inheritance relationship in their sources.
4022 QualType FromType1 = SCS1.getFromType();
4023 QualType FromType2 = SCS2.getFromType();
4024
4025 // Adjust the types we're converting from via the array-to-pointer
4026 // conversion, if we need to.
4027 if (SCS1.First == ICK_Array_To_Pointer)
4028 FromType1 = S.Context.getArrayDecayedType(FromType1);
4029 if (SCS2.First == ICK_Array_To_Pointer)
4030 FromType2 = S.Context.getArrayDecayedType(FromType2);
4031
4032 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
4033 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
4034
4035 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4036 return ImplicitConversionSequence::Better;
4037 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4038 return ImplicitConversionSequence::Worse;
4039
4040 // Objective-C++: If one interface is more specific than the
4041 // other, it is the better one.
4042 const ObjCObjectPointerType* FromObjCPtr1
4043 = FromType1->getAs<ObjCObjectPointerType>();
4044 const ObjCObjectPointerType* FromObjCPtr2
4045 = FromType2->getAs<ObjCObjectPointerType>();
4046 if (FromObjCPtr1 && FromObjCPtr2) {
4047 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
4048 FromObjCPtr2);
4049 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
4050 FromObjCPtr1);
4051 if (AssignLeft != AssignRight) {
4052 return AssignLeft? ImplicitConversionSequence::Better
4053 : ImplicitConversionSequence::Worse;
4054 }
4055 }
4056 }
4057
4058 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
4059 // Check for a better reference binding based on the kind of bindings.
4060 if (isBetterReferenceBindingKind(SCS1, SCS2))
4061 return ImplicitConversionSequence::Better;
4062 else if (isBetterReferenceBindingKind(SCS2, SCS1))
4063 return ImplicitConversionSequence::Worse;
4064 }
4065
4066 // Compare based on qualification conversions (C++ 13.3.3.2p3,
4067 // bullet 3).
4068 if (ImplicitConversionSequence::CompareKind QualCK
4069 = CompareQualificationConversions(S, SCS1, SCS2))
4070 return QualCK;
4071
4072 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
4073 // C++ [over.ics.rank]p3b4:
4074 // -- S1 and S2 are reference bindings (8.5.3), and the types to
4075 // which the references refer are the same type except for
4076 // top-level cv-qualifiers, and the type to which the reference
4077 // initialized by S2 refers is more cv-qualified than the type
4078 // to which the reference initialized by S1 refers.
4079 QualType T1 = SCS1.getToType(2);
4080 QualType T2 = SCS2.getToType(2);
4081 T1 = S.Context.getCanonicalType(T1);
4082 T2 = S.Context.getCanonicalType(T2);
4083 Qualifiers T1Quals, T2Quals;
4084 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
4085 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
4086 if (UnqualT1 == UnqualT2) {
4087 // Objective-C++ ARC: If the references refer to objects with different
4088 // lifetimes, prefer bindings that don't change lifetime.
4089 if (SCS1.ObjCLifetimeConversionBinding !=
4090 SCS2.ObjCLifetimeConversionBinding) {
4091 return SCS1.ObjCLifetimeConversionBinding
4092 ? ImplicitConversionSequence::Worse
4093 : ImplicitConversionSequence::Better;
4094 }
4095
4096 // If the type is an array type, promote the element qualifiers to the
4097 // type for comparison.
4098 if (isa<ArrayType>(T1) && T1Quals)
4099 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
4100 if (isa<ArrayType>(T2) && T2Quals)
4101 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
4102 if (T2.isMoreQualifiedThan(T1))
4103 return ImplicitConversionSequence::Better;
4104 if (T1.isMoreQualifiedThan(T2))
4105 return ImplicitConversionSequence::Worse;
4106 }
4107 }
4108
4109 // In Microsoft mode, prefer an integral conversion to a
4110 // floating-to-integral conversion if the integral conversion
4111 // is between types of the same size.
4112 // For example:
4113 // void f(float);
4114 // void f(int);
4115 // int main {
4116 // long a;
4117 // f(a);
4118 // }
4119 // Here, MSVC will call f(int) instead of generating a compile error
4120 // as clang will do in standard mode.
4121 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
4122 SCS2.Second == ICK_Floating_Integral &&
4123 S.Context.getTypeSize(SCS1.getFromType()) ==
4124 S.Context.getTypeSize(SCS1.getToType(2)))
4125 return ImplicitConversionSequence::Better;
4126
4127 // Prefer a compatible vector conversion over a lax vector conversion
4128 // For example:
4129 //
4130 // typedef float __v4sf __attribute__((__vector_size__(16)));
4131 // void f(vector float);
4132 // void f(vector signed int);
4133 // int main() {
4134 // __v4sf a;
4135 // f(a);
4136 // }
4137 // Here, we'd like to choose f(vector float) and not
4138 // report an ambiguous call error
4139 if (SCS1.Second == ICK_Vector_Conversion &&
4140 SCS2.Second == ICK_Vector_Conversion) {
4141 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4142 SCS1.getFromType(), SCS1.getToType(2));
4143 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4144 SCS2.getFromType(), SCS2.getToType(2));
4145
4146 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
4147 return SCS1IsCompatibleVectorConversion
4148 ? ImplicitConversionSequence::Better
4149 : ImplicitConversionSequence::Worse;
4150 }
4151
4152 if (SCS1.Second == ICK_SVE_Vector_Conversion &&
4153 SCS2.Second == ICK_SVE_Vector_Conversion) {
4154 bool SCS1IsCompatibleSVEVectorConversion =
4155 S.Context.areCompatibleSveTypes(SCS1.getFromType(), SCS1.getToType(2));
4156 bool SCS2IsCompatibleSVEVectorConversion =
4157 S.Context.areCompatibleSveTypes(SCS2.getFromType(), SCS2.getToType(2));
4158
4159 if (SCS1IsCompatibleSVEVectorConversion !=
4160 SCS2IsCompatibleSVEVectorConversion)
4161 return SCS1IsCompatibleSVEVectorConversion
4162 ? ImplicitConversionSequence::Better
4163 : ImplicitConversionSequence::Worse;
4164 }
4165
4166 return ImplicitConversionSequence::Indistinguishable;
4167}
4168
4169/// CompareQualificationConversions - Compares two standard conversion
4170/// sequences to determine whether they can be ranked based on their
4171/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
4172static ImplicitConversionSequence::CompareKind
4173CompareQualificationConversions(Sema &S,
4174 const StandardConversionSequence& SCS1,
4175 const StandardConversionSequence& SCS2) {
4176 // C++ 13.3.3.2p3:
4177 // -- S1 and S2 differ only in their qualification conversion and
4178 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
4179 // cv-qualification signature of type T1 is a proper subset of
4180 // the cv-qualification signature of type T2, and S1 is not the
4181 // deprecated string literal array-to-pointer conversion (4.2).
4182 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
4183 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
4184 return ImplicitConversionSequence::Indistinguishable;
4185
4186 // FIXME: the example in the standard doesn't use a qualification
4187 // conversion (!)
4188 QualType T1 = SCS1.getToType(2);
4189 QualType T2 = SCS2.getToType(2);
4190 T1 = S.Context.getCanonicalType(T1);
4191 T2 = S.Context.getCanonicalType(T2);
4192 assert(!T1->isReferenceType() && !T2->isReferenceType());
4193 Qualifiers T1Quals, T2Quals;
4194 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
4195 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
4196
4197 // If the types are the same, we won't learn anything by unwrapping
4198 // them.
4199 if (UnqualT1 == UnqualT2)
4200 return ImplicitConversionSequence::Indistinguishable;
4201
4202 ImplicitConversionSequence::CompareKind Result
4203 = ImplicitConversionSequence::Indistinguishable;
4204
4205 // Objective-C++ ARC:
4206 // Prefer qualification conversions not involving a change in lifetime
4207 // to qualification conversions that do not change lifetime.
4208 if (SCS1.QualificationIncludesObjCLifetime !=
4209 SCS2.QualificationIncludesObjCLifetime) {
4210 Result = SCS1.QualificationIncludesObjCLifetime
4211 ? ImplicitConversionSequence::Worse
4212 : ImplicitConversionSequence::Better;
4213 }
4214
4215 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
4216 // Within each iteration of the loop, we check the qualifiers to
4217 // determine if this still looks like a qualification
4218 // conversion. Then, if all is well, we unwrap one more level of
4219 // pointers or pointers-to-members and do it all again
4220 // until there are no more pointers or pointers-to-members left
4221 // to unwrap. This essentially mimics what
4222 // IsQualificationConversion does, but here we're checking for a
4223 // strict subset of qualifiers.
4224 if (T1.getQualifiers().withoutObjCLifetime() ==
4225 T2.getQualifiers().withoutObjCLifetime())
4226 // The qualifiers are the same, so this doesn't tell us anything
4227 // about how the sequences rank.
4228 // ObjC ownership quals are omitted above as they interfere with
4229 // the ARC overload rule.
4230 ;
4231 else if (T2.isMoreQualifiedThan(T1)) {
4232 // T1 has fewer qualifiers, so it could be the better sequence.
4233 if (Result == ImplicitConversionSequence::Worse)
4234 // Neither has qualifiers that are a subset of the other's
4235 // qualifiers.
4236 return ImplicitConversionSequence::Indistinguishable;
4237
4238 Result = ImplicitConversionSequence::Better;
4239 } else if (T1.isMoreQualifiedThan(T2)) {
4240 // T2 has fewer qualifiers, so it could be the better sequence.
4241 if (Result == ImplicitConversionSequence::Better)
4242 // Neither has qualifiers that are a subset of the other's
4243 // qualifiers.
4244 return ImplicitConversionSequence::Indistinguishable;
4245
4246 Result = ImplicitConversionSequence::Worse;
4247 } else {
4248 // Qualifiers are disjoint.
4249 return ImplicitConversionSequence::Indistinguishable;
4250 }
4251
4252 // If the types after this point are equivalent, we're done.
4253 if (S.Context.hasSameUnqualifiedType(T1, T2))
4254 break;
4255 }
4256
4257 // Check that the winning standard conversion sequence isn't using
4258 // the deprecated string literal array to pointer conversion.
4259 switch (Result) {
4260 case ImplicitConversionSequence::Better:
4261 if (SCS1.DeprecatedStringLiteralToCharPtr)
4262 Result = ImplicitConversionSequence::Indistinguishable;
4263 break;
4264
4265 case ImplicitConversionSequence::Indistinguishable:
4266 break;
4267
4268 case ImplicitConversionSequence::Worse:
4269 if (SCS2.DeprecatedStringLiteralToCharPtr)
4270 Result = ImplicitConversionSequence::Indistinguishable;
4271 break;
4272 }
4273
4274 return Result;
4275}
4276
4277/// CompareDerivedToBaseConversions - Compares two standard conversion
4278/// sequences to determine whether they can be ranked based on their
4279/// various kinds of derived-to-base conversions (C++
4280/// [over.ics.rank]p4b3). As part of these checks, we also look at
4281/// conversions between Objective-C interface types.
4282static ImplicitConversionSequence::CompareKind
4283CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4284 const StandardConversionSequence& SCS1,
4285 const StandardConversionSequence& SCS2) {
4286 QualType FromType1 = SCS1.getFromType();
4287 QualType ToType1 = SCS1.getToType(1);
4288 QualType FromType2 = SCS2.getFromType();
4289 QualType ToType2 = SCS2.getToType(1);
4290
4291 // Adjust the types we're converting from via the array-to-pointer
4292 // conversion, if we need to.
4293 if (SCS1.First == ICK_Array_To_Pointer)
4294 FromType1 = S.Context.getArrayDecayedType(FromType1);
4295 if (SCS2.First == ICK_Array_To_Pointer)
4296 FromType2 = S.Context.getArrayDecayedType(FromType2);
4297
4298 // Canonicalize all of the types.
4299 FromType1 = S.Context.getCanonicalType(FromType1);
4300 ToType1 = S.Context.getCanonicalType(ToType1);
4301 FromType2 = S.Context.getCanonicalType(FromType2);
4302 ToType2 = S.Context.getCanonicalType(ToType2);
4303
4304 // C++ [over.ics.rank]p4b3:
4305 //
4306 // If class B is derived directly or indirectly from class A and
4307 // class C is derived directly or indirectly from B,
4308 //
4309 // Compare based on pointer conversions.
4310 if (SCS1.Second == ICK_Pointer_Conversion &&
4311 SCS2.Second == ICK_Pointer_Conversion &&
4312 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4313 FromType1->isPointerType() && FromType2->isPointerType() &&
4314 ToType1->isPointerType() && ToType2->isPointerType()) {
4315 QualType FromPointee1 =
4316 FromType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4317 QualType ToPointee1 =
4318 ToType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4319 QualType FromPointee2 =
4320 FromType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4321 QualType ToPointee2 =
4322 ToType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4323
4324 // -- conversion of C* to B* is better than conversion of C* to A*,
4325 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4326 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4327 return ImplicitConversionSequence::Better;
4328 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4329 return ImplicitConversionSequence::Worse;
4330 }
4331
4332 // -- conversion of B* to A* is better than conversion of C* to A*,
4333 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4334 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4335 return ImplicitConversionSequence::Better;
4336 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4337 return ImplicitConversionSequence::Worse;
4338 }
4339 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4340 SCS2.Second == ICK_Pointer_Conversion) {
4341 const ObjCObjectPointerType *FromPtr1
4342 = FromType1->getAs<ObjCObjectPointerType>();
4343 const ObjCObjectPointerType *FromPtr2
4344 = FromType2->getAs<ObjCObjectPointerType>();
4345 const ObjCObjectPointerType *ToPtr1
4346 = ToType1->getAs<ObjCObjectPointerType>();
4347 const ObjCObjectPointerType *ToPtr2
4348 = ToType2->getAs<ObjCObjectPointerType>();
4349
4350 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4351 // Apply the same conversion ranking rules for Objective-C pointer types
4352 // that we do for C++ pointers to class types. However, we employ the
4353 // Objective-C pseudo-subtyping relationship used for assignment of
4354 // Objective-C pointer types.
4355 bool FromAssignLeft
4356 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4357 bool FromAssignRight
4358 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4359 bool ToAssignLeft
4360 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4361 bool ToAssignRight
4362 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4363
4364 // A conversion to an a non-id object pointer type or qualified 'id'
4365 // type is better than a conversion to 'id'.
4366 if (ToPtr1->isObjCIdType() &&
4367 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4368 return ImplicitConversionSequence::Worse;
4369 if (ToPtr2->isObjCIdType() &&
4370 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4371 return ImplicitConversionSequence::Better;
4372
4373 // A conversion to a non-id object pointer type is better than a
4374 // conversion to a qualified 'id' type
4375 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4376 return ImplicitConversionSequence::Worse;
4377 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4378 return ImplicitConversionSequence::Better;
4379
4380 // A conversion to an a non-Class object pointer type or qualified 'Class'
4381 // type is better than a conversion to 'Class'.
4382 if (ToPtr1->isObjCClassType() &&
4383 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4384 return ImplicitConversionSequence::Worse;
4385 if (ToPtr2->isObjCClassType() &&
4386 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4387 return ImplicitConversionSequence::Better;
4388
4389 // A conversion to a non-Class object pointer type is better than a
4390 // conversion to a qualified 'Class' type.
4391 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4392 return ImplicitConversionSequence::Worse;
4393 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4394 return ImplicitConversionSequence::Better;
4395
4396 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4397 if (S.Context.hasSameType(FromType1, FromType2) &&
4398 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4399 (ToAssignLeft != ToAssignRight)) {
4400 if (FromPtr1->isSpecialized()) {
4401 // "conversion of B<A> * to B * is better than conversion of B * to
4402 // C *.
4403 bool IsFirstSame =
4404 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4405 bool IsSecondSame =
4406 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4407 if (IsFirstSame) {
4408 if (!IsSecondSame)
4409 return ImplicitConversionSequence::Better;
4410 } else if (IsSecondSame)
4411 return ImplicitConversionSequence::Worse;
4412 }
4413 return ToAssignLeft? ImplicitConversionSequence::Worse
4414 : ImplicitConversionSequence::Better;
4415 }
4416
4417 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4418 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4419 (FromAssignLeft != FromAssignRight))
4420 return FromAssignLeft? ImplicitConversionSequence::Better
4421 : ImplicitConversionSequence::Worse;
4422 }
4423 }
4424
4425 // Ranking of member-pointer types.
4426 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4427 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4428 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4429 const auto *FromMemPointer1 = FromType1->castAs<MemberPointerType>();
4430 const auto *ToMemPointer1 = ToType1->castAs<MemberPointerType>();
4431 const auto *FromMemPointer2 = FromType2->castAs<MemberPointerType>();
4432 const auto *ToMemPointer2 = ToType2->castAs<MemberPointerType>();
4433 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4434 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4435 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4436 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4437 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4438 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4439 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4440 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4441 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4442 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4443 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4444 return ImplicitConversionSequence::Worse;
4445 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4446 return ImplicitConversionSequence::Better;
4447 }
4448 // conversion of B::* to C::* is better than conversion of A::* to C::*
4449 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4450 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4451 return ImplicitConversionSequence::Better;
4452 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4453 return ImplicitConversionSequence::Worse;
4454 }
4455 }
4456
4457 if (SCS1.Second == ICK_Derived_To_Base) {
4458 // -- conversion of C to B is better than conversion of C to A,
4459 // -- binding of an expression of type C to a reference of type
4460 // B& is better than binding an expression of type C to a
4461 // reference of type A&,
4462 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4463 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4464 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4465 return ImplicitConversionSequence::Better;
4466 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4467 return ImplicitConversionSequence::Worse;
4468 }
4469
4470 // -- conversion of B to A is better than conversion of C to A.
4471 // -- binding of an expression of type B to a reference of type
4472 // A& is better than binding an expression of type C to a
4473 // reference of type A&,
4474 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4475 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4476 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4477 return ImplicitConversionSequence::Better;
4478 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4479 return ImplicitConversionSequence::Worse;
4480 }
4481 }
4482
4483 return ImplicitConversionSequence::Indistinguishable;
4484}
4485
4486/// Determine whether the given type is valid, e.g., it is not an invalid
4487/// C++ class.
4488static bool isTypeValid(QualType T) {
4489 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4490 return !Record->isInvalidDecl();
4491
4492 return true;
4493}
4494
4495static QualType withoutUnaligned(ASTContext &Ctx, QualType T) {
4496 if (!T.getQualifiers().hasUnaligned())
4497 return T;
4498
4499 Qualifiers Q;
4500 T = Ctx.getUnqualifiedArrayType(T, Q);
4501 Q.removeUnaligned();
4502 return Ctx.getQualifiedType(T, Q);
4503}
4504
4505/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4506/// determine whether they are reference-compatible,
4507/// reference-related, or incompatible, for use in C++ initialization by
4508/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4509/// type, and the first type (T1) is the pointee type of the reference
4510/// type being initialized.
4511Sema::ReferenceCompareResult
4512Sema::CompareReferenceRelationship(SourceLocation Loc,
4513 QualType OrigT1, QualType OrigT2,
4514 ReferenceConversions *ConvOut) {
4515 assert(!OrigT1->isReferenceType() &&
4516 "T1 must be the pointee type of the reference type");
4517 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4518
4519 QualType T1 = Context.getCanonicalType(OrigT1);
4520 QualType T2 = Context.getCanonicalType(OrigT2);
4521 Qualifiers T1Quals, T2Quals;
4522 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4523 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4524
4525 ReferenceConversions ConvTmp;
4526 ReferenceConversions &Conv = ConvOut ? *ConvOut : ConvTmp;
4527 Conv = ReferenceConversions();
4528
4529 // C++2a [dcl.init.ref]p4:
4530 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4531 // reference-related to "cv2 T2" if T1 is similar to T2, or
4532 // T1 is a base class of T2.
4533 // "cv1 T1" is reference-compatible with "cv2 T2" if
4534 // a prvalue of type "pointer to cv2 T2" can be converted to the type
4535 // "pointer to cv1 T1" via a standard conversion sequence.
4536
4537 // Check for standard conversions we can apply to pointers: derived-to-base
4538 // conversions, ObjC pointer conversions, and function pointer conversions.
4539 // (Qualification conversions are checked last.)
4540 QualType ConvertedT2;
4541 if (UnqualT1 == UnqualT2) {
4542 // Nothing to do.
4543 } else if (isCompleteType(Loc, OrigT2) &&
4544 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4545 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4546 Conv |= ReferenceConversions::DerivedToBase;
4547 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4548 UnqualT2->isObjCObjectOrInterfaceType() &&
4549 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4550 Conv |= ReferenceConversions::ObjC;
4551 else if (UnqualT2->isFunctionType() &&
4552 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2)) {
4553 Conv |= ReferenceConversions::Function;
4554 // No need to check qualifiers; function types don't have them.
4555 return Ref_Compatible;
4556 }
4557 bool ConvertedReferent = Conv != 0;
4558
4559 // We can have a qualification conversion. Compute whether the types are
4560 // similar at the same time.
4561 bool PreviousToQualsIncludeConst = true;
4562 bool TopLevel = true;
4563 do {
4564 if (T1 == T2)
4565 break;
4566
4567 // We will need a qualification conversion.
4568 Conv |= ReferenceConversions::Qualification;
4569
4570 // Track whether we performed a qualification conversion anywhere other
4571 // than the top level. This matters for ranking reference bindings in
4572 // overload resolution.
4573 if (!TopLevel)
4574 Conv |= ReferenceConversions::NestedQualification;
4575
4576 // MS compiler ignores __unaligned qualifier for references; do the same.
4577 T1 = withoutUnaligned(Context, T1);
4578 T2 = withoutUnaligned(Context, T2);
4579
4580 // If we find a qualifier mismatch, the types are not reference-compatible,
4581 // but are still be reference-related if they're similar.
4582 bool ObjCLifetimeConversion = false;
4583 if (!isQualificationConversionStep(T2, T1, /*CStyle=*/false, TopLevel,
4584 PreviousToQualsIncludeConst,
4585 ObjCLifetimeConversion))
4586 return (ConvertedReferent || Context.hasSimilarType(T1, T2))
4587 ? Ref_Related
4588 : Ref_Incompatible;
4589
4590 // FIXME: Should we track this for any level other than the first?
4591 if (ObjCLifetimeConversion)
4592 Conv |= ReferenceConversions::ObjCLifetime;
4593
4594 TopLevel = false;
4595 } while (Context.UnwrapSimilarTypes(T1, T2));
4596
4597 // At this point, if the types are reference-related, we must either have the
4598 // same inner type (ignoring qualifiers), or must have already worked out how
4599 // to convert the referent.
4600 return (ConvertedReferent || Context.hasSameUnqualifiedType(T1, T2))
4601 ? Ref_Compatible
4602 : Ref_Incompatible;
4603}
4604
4605/// Look for a user-defined conversion to a value reference-compatible
4606/// with DeclType. Return true if something definite is found.
4607static bool
4608FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4609 QualType DeclType, SourceLocation DeclLoc,
4610 Expr *Init, QualType T2, bool AllowRvalues,
4611 bool AllowExplicit) {
4612 assert(T2->isRecordType() && "Can only find conversions of record types.");
4613 auto *T2RecordDecl = cast<CXXRecordDecl>(T2->castAs<RecordType>()->getDecl());
4614
4615 OverloadCandidateSet CandidateSet(
4616 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4617 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4618 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4619 NamedDecl *D = *I;
4620 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4621 if (isa<UsingShadowDecl>(D))
4622 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4623
4624 FunctionTemplateDecl *ConvTemplate
4625 = dyn_cast<FunctionTemplateDecl>(D);
4626 CXXConversionDecl *Conv;
4627 if (ConvTemplate)
4628 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4629 else
4630 Conv = cast<CXXConversionDecl>(D);
4631
4632 if (AllowRvalues) {
4633 // If we are initializing an rvalue reference, don't permit conversion
4634 // functions that return lvalues.
4635 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4636 const ReferenceType *RefType
4637 = Conv->getConversionType()->getAs<LValueReferenceType>();
4638 if (RefType && !RefType->getPointeeType()->isFunctionType())
4639 continue;
4640 }
4641
4642 if (!ConvTemplate &&
4643 S.CompareReferenceRelationship(
4644 DeclLoc,
4645 Conv->getConversionType()
4646 .getNonReferenceType()
4647 .getUnqualifiedType(),
4648 DeclType.getNonReferenceType().getUnqualifiedType()) ==
4649 Sema::Ref_Incompatible)
4650 continue;
4651 } else {
4652 // If the conversion function doesn't return a reference type,
4653 // it can't be considered for this conversion. An rvalue reference
4654 // is only acceptable if its referencee is a function type.
4655
4656 const ReferenceType *RefType =
4657 Conv->getConversionType()->getAs<ReferenceType>();
4658 if (!RefType ||
4659 (!RefType->isLValueReferenceType() &&
4660 !RefType->getPointeeType()->isFunctionType()))
4661 continue;
4662 }
4663
4664 if (ConvTemplate)
4665 S.AddTemplateConversionCandidate(
4666 ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4667 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4668 else
4669 S.AddConversionCandidate(
4670 Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4671 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4672 }
4673
4674 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4675
4676 OverloadCandidateSet::iterator Best;
4677 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4678 case OR_Success:
4679 // C++ [over.ics.ref]p1:
4680 //
4681 // [...] If the parameter binds directly to the result of
4682 // applying a conversion function to the argument
4683 // expression, the implicit conversion sequence is a
4684 // user-defined conversion sequence (13.3.3.1.2), with the
4685 // second standard conversion sequence either an identity
4686 // conversion or, if the conversion function returns an
4687 // entity of a type that is a derived class of the parameter
4688 // type, a derived-to-base Conversion.
4689 if (!Best->FinalConversion.DirectBinding)
4690 return false;
4691
4692 ICS.setUserDefined();
4693 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4694 ICS.UserDefined.After = Best->FinalConversion;
4695 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4696 ICS.UserDefined.ConversionFunction = Best->Function;
4697 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4698 ICS.UserDefined.EllipsisConversion = false;
4699 assert(ICS.UserDefined.After.ReferenceBinding &&
4700 ICS.UserDefined.After.DirectBinding &&
4701 "Expected a direct reference binding!");
4702 return true;
4703
4704 case OR_Ambiguous:
4705 ICS.setAmbiguous();
4706 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4707 Cand != CandidateSet.end(); ++Cand)
4708 if (Cand->Best)
4709 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4710 return true;
4711
4712 case OR_No_Viable_Function:
4713 case OR_Deleted:
4714 // There was no suitable conversion, or we found a deleted
4715 // conversion; continue with other checks.
4716 return false;
4717 }
4718
4719 llvm_unreachable("Invalid OverloadResult!");
4720}
4721
4722/// Compute an implicit conversion sequence for reference
4723/// initialization.
4724static ImplicitConversionSequence
4725TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4726 SourceLocation DeclLoc,
4727 bool SuppressUserConversions,
4728 bool AllowExplicit) {
4729 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4730
4731 // Most paths end in a failed conversion.
4732 ImplicitConversionSequence ICS;
4733 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4734
4735 QualType T1 = DeclType->castAs<ReferenceType>()->getPointeeType();
4736 QualType T2 = Init->getType();
4737
4738 // If the initializer is the address of an overloaded function, try
4739 // to resolve the overloaded function. If all goes well, T2 is the
4740 // type of the resulting function.
4741 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4742 DeclAccessPair Found;
4743 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4744 false, Found))
4745 T2 = Fn->getType();
4746 }
4747
4748 // Compute some basic properties of the types and the initializer.
4749 bool isRValRef = DeclType->isRValueReferenceType();
4750 Expr::Classification InitCategory = Init->Classify(S.Context);
4751
4752 Sema::ReferenceConversions RefConv;
4753 Sema::ReferenceCompareResult RefRelationship =
4754 S.CompareReferenceRelationship(DeclLoc, T1, T2, &RefConv);
4755
4756 auto SetAsReferenceBinding = [&](bool BindsDirectly) {
4757 ICS.setStandard();
4758 ICS.Standard.First = ICK_Identity;
4759 // FIXME: A reference binding can be a function conversion too. We should
4760 // consider that when ordering reference-to-function bindings.
4761 ICS.Standard.Second = (RefConv & Sema::ReferenceConversions::DerivedToBase)
4762 ? ICK_Derived_To_Base
4763 : (RefConv & Sema::ReferenceConversions::ObjC)
4764 ? ICK_Compatible_Conversion
4765 : ICK_Identity;
4766 // FIXME: As a speculative fix to a defect introduced by CWG2352, we rank
4767 // a reference binding that performs a non-top-level qualification
4768 // conversion as a qualification conversion, not as an identity conversion.
4769 ICS.Standard.Third = (RefConv &
4770 Sema::ReferenceConversions::NestedQualification)
4771 ? ICK_Qualification
4772 : ICK_Identity;
4773 ICS.Standard.setFromType(T2);
4774 ICS.Standard.setToType(0, T2);
4775 ICS.Standard.setToType(1, T1);
4776 ICS.Standard.setToType(2, T1);
4777 ICS.Standard.ReferenceBinding = true;
4778 ICS.Standard.DirectBinding = BindsDirectly;
4779 ICS.Standard.IsLvalueReference = !isRValRef;
4780 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4781 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4782 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4783 ICS.Standard.ObjCLifetimeConversionBinding =
4784 (RefConv & Sema::ReferenceConversions::ObjCLifetime) != 0;
4785 ICS.Standard.CopyConstructor = nullptr;
4786 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4787 };
4788
4789 // C++0x [dcl.init.ref]p5:
4790 // A reference to type "cv1 T1" is initialized by an expression
4791 // of type "cv2 T2" as follows:
4792
4793 // -- If reference is an lvalue reference and the initializer expression
4794 if (!isRValRef) {
4795 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4796 // reference-compatible with "cv2 T2," or
4797 //
4798 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4799 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4800 // C++ [over.ics.ref]p1:
4801 // When a parameter of reference type binds directly (8.5.3)
4802 // to an argument expression, the implicit conversion sequence
4803 // is the identity conversion, unless the argument expression
4804 // has a type that is a derived class of the parameter type,
4805 // in which case the implicit conversion sequence is a
4806 // derived-to-base Conversion (13.3.3.1).
4807 SetAsReferenceBinding(/*BindsDirectly=*/true);
4808
4809 // Nothing more to do: the inaccessibility/ambiguity check for
4810 // derived-to-base conversions is suppressed when we're
4811 // computing the implicit conversion sequence (C++
4812 // [over.best.ics]p2).
4813 return ICS;
4814 }
4815
4816 // -- has a class type (i.e., T2 is a class type), where T1 is
4817 // not reference-related to T2, and can be implicitly
4818 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4819 // is reference-compatible with "cv3 T3" 92) (this
4820 // conversion is selected by enumerating the applicable
4821 // conversion functions (13.3.1.6) and choosing the best
4822 // one through overload resolution (13.3)),
4823 if (!SuppressUserConversions && T2->isRecordType() &&
4824 S.isCompleteType(DeclLoc, T2) &&
4825 RefRelationship == Sema::Ref_Incompatible) {
4826 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4827 Init, T2, /*AllowRvalues=*/false,
4828 AllowExplicit))
4829 return ICS;
4830 }
4831 }
4832
4833 // -- Otherwise, the reference shall be an lvalue reference to a
4834 // non-volatile const type (i.e., cv1 shall be const), or the reference
4835 // shall be an rvalue reference.
4836 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) {
4837 if (InitCategory.isRValue() && RefRelationship != Sema::Ref_Incompatible)
4838 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4839 return ICS;
4840 }
4841
4842 // -- If the initializer expression
4843 //
4844 // -- is an xvalue, class prvalue, array prvalue or function
4845 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4846 if (RefRelationship == Sema::Ref_Compatible &&
4847 (InitCategory.isXValue() ||
4848 (InitCategory.isPRValue() &&
4849 (T2->isRecordType() || T2->isArrayType())) ||
4850 (InitCategory.isLValue() && T2->isFunctionType()))) {
4851 // In C++11, this is always a direct binding. In C++98/03, it's a direct
4852 // binding unless we're binding to a class prvalue.
4853 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4854 // allow the use of rvalue references in C++98/03 for the benefit of
4855 // standard library implementors; therefore, we need the xvalue check here.
4856 SetAsReferenceBinding(/*BindsDirectly=*/S.getLangOpts().CPlusPlus11 ||
4857 !(InitCategory.isPRValue() || T2->isRecordType()));
4858 return ICS;
4859 }
4860
4861 // -- has a class type (i.e., T2 is a class type), where T1 is not
4862 // reference-related to T2, and can be implicitly converted to
4863 // an xvalue, class prvalue, or function lvalue of type
4864 // "cv3 T3", where "cv1 T1" is reference-compatible with
4865 // "cv3 T3",
4866 //
4867 // then the reference is bound to the value of the initializer
4868 // expression in the first case and to the result of the conversion
4869 // in the second case (or, in either case, to an appropriate base
4870 // class subobject).
4871 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4872 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4873 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4874 Init, T2, /*AllowRvalues=*/true,
4875 AllowExplicit)) {
4876 // In the second case, if the reference is an rvalue reference
4877 // and the second standard conversion sequence of the
4878 // user-defined conversion sequence includes an lvalue-to-rvalue
4879 // conversion, the program is ill-formed.
4880 if (ICS.isUserDefined() && isRValRef &&
4881 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4882 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4883
4884 return ICS;
4885 }
4886
4887 // A temporary of function type cannot be created; don't even try.
4888 if (T1->isFunctionType())
4889 return ICS;
4890
4891 // -- Otherwise, a temporary of type "cv1 T1" is created and
4892 // initialized from the initializer expression using the
4893 // rules for a non-reference copy initialization (8.5). The
4894 // reference is then bound to the temporary. If T1 is
4895 // reference-related to T2, cv1 must be the same
4896 // cv-qualification as, or greater cv-qualification than,
4897 // cv2; otherwise, the program is ill-formed.
4898 if (RefRelationship == Sema::Ref_Related) {
4899 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4900 // we would be reference-compatible or reference-compatible with
4901 // added qualification. But that wasn't the case, so the reference
4902 // initialization fails.
4903 //
4904 // Note that we only want to check address spaces and cvr-qualifiers here.
4905 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4906 Qualifiers T1Quals = T1.getQualifiers();
4907 Qualifiers T2Quals = T2.getQualifiers();
4908 T1Quals.removeObjCGCAttr();
4909 T1Quals.removeObjCLifetime();
4910 T2Quals.removeObjCGCAttr();
4911 T2Quals.removeObjCLifetime();
4912 // MS compiler ignores __unaligned qualifier for references; do the same.
4913 T1Quals.removeUnaligned();
4914 T2Quals.removeUnaligned();
4915 if (!T1Quals.compatiblyIncludes(T2Quals))
4916 return ICS;
4917 }
4918
4919 // If at least one of the types is a class type, the types are not
4920 // related, and we aren't allowed any user conversions, the
4921 // reference binding fails. This case is important for breaking
4922 // recursion, since TryImplicitConversion below will attempt to
4923 // create a temporary through the use of a copy constructor.
4924 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4925 (T1->isRecordType() || T2->isRecordType()))
4926 return ICS;
4927
4928 // If T1 is reference-related to T2 and the reference is an rvalue
4929 // reference, the initializer expression shall not be an lvalue.
4930 if (RefRelationship >= Sema::Ref_Related && isRValRef &&
4931 Init->Classify(S.Context).isLValue()) {
4932 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, Init, DeclType);
4933 return ICS;
4934 }
4935
4936 // C++ [over.ics.ref]p2:
4937 // When a parameter of reference type is not bound directly to
4938 // an argument expression, the conversion sequence is the one
4939 // required to convert the argument expression to the
4940 // underlying type of the reference according to
4941 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4942 // to copy-initializing a temporary of the underlying type with
4943 // the argument expression. Any difference in top-level
4944 // cv-qualification is subsumed by the initialization itself
4945 // and does not constitute a conversion.
4946 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4947 AllowedExplicit::None,
4948 /*InOverloadResolution=*/false,
4949 /*CStyle=*/false,
4950 /*AllowObjCWritebackConversion=*/false,
4951 /*AllowObjCConversionOnExplicit=*/false);
4952
4953 // Of course, that's still a reference binding.
4954 if (ICS.isStandard()) {
4955 ICS.Standard.ReferenceBinding = true;
4956 ICS.Standard.IsLvalueReference = !isRValRef;
4957 ICS.Standard.BindsToFunctionLvalue = false;
4958 ICS.Standard.BindsToRvalue = true;
4959 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4960 ICS.Standard.ObjCLifetimeConversionBinding = false;
4961 } else if (ICS.isUserDefined()) {
4962 const ReferenceType *LValRefType =
4963 ICS.UserDefined.ConversionFunction->getReturnType()
4964 ->getAs<LValueReferenceType>();
4965
4966 // C++ [over.ics.ref]p3:
4967 // Except for an implicit object parameter, for which see 13.3.1, a
4968 // standard conversion sequence cannot be formed if it requires [...]
4969 // binding an rvalue reference to an lvalue other than a function
4970 // lvalue.
4971 // Note that the function case is not possible here.
4972 if (isRValRef && LValRefType) {
4973 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4974 return ICS;
4975 }
4976
4977 ICS.UserDefined.After.ReferenceBinding = true;
4978 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4979 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4980 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4981 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4982 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4983 }
4984
4985 return ICS;
4986}
4987
4988static ImplicitConversionSequence
4989TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4990 bool SuppressUserConversions,
4991 bool InOverloadResolution,
4992 bool AllowObjCWritebackConversion,
4993 bool AllowExplicit = false);
4994
4995/// TryListConversion - Try to copy-initialize a value of type ToType from the
4996/// initializer list From.
4997static ImplicitConversionSequence
4998TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4999 bool SuppressUserConversions,
5000 bool InOverloadResolution,
5001 bool AllowObjCWritebackConversion) {
5002 // C++11 [over.ics.list]p1:
5003 // When an argument is an initializer list, it is not an expression and
5004 // special rules apply for converting it to a parameter type.
5005
5006 ImplicitConversionSequence Result;
5007 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
5008
5009 // We need a complete type for what follows. Incomplete types can never be
5010 // initialized from init lists.
5011 if (!S.isCompleteType(From->getBeginLoc(), ToType))
5012 return Result;
5013
5014 // Per DR1467:
5015 // If the parameter type is a class X and the initializer list has a single
5016 // element of type cv U, where U is X or a class derived from X, the
5017 // implicit conversion sequence is the one required to convert the element
5018 // to the parameter type.
5019 //
5020 // Otherwise, if the parameter type is a character array [... ]
5021 // and the initializer list has a single element that is an
5022 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
5023 // implicit conversion sequence is the identity conversion.
5024 if (From->getNumInits() == 1) {
5025 if (ToType->isRecordType()) {
5026 QualType InitType = From->getInit(0)->getType();
5027 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
5028 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
5029 return TryCopyInitialization(S, From->getInit(0), ToType,
5030 SuppressUserConversions,
5031 InOverloadResolution,
5032 AllowObjCWritebackConversion);
5033 }
5034
5035 if (const auto *AT = S.Context.getAsArrayType(ToType)) {
5036 if (S.IsStringInit(From->getInit(0), AT)) {
5037 InitializedEntity Entity =
5038 InitializedEntity::InitializeParameter(S.Context, ToType,
5039 /*Consumed=*/false);
5040 if (S.CanPerformCopyInitialization(Entity, From)) {
5041 Result.setStandard();
5042 Result.Standard.setAsIdentityConversion();
5043 Result.Standard.setFromType(ToType);
5044 Result.Standard.setAllToTypes(ToType);
5045 return Result;
5046 }
5047 }
5048 }
5049 }
5050
5051 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
5052 // C++11 [over.ics.list]p2:
5053 // If the parameter type is std::initializer_list<X> or "array of X" and
5054 // all the elements can be implicitly converted to X, the implicit
5055 // conversion sequence is the worst conversion necessary to convert an
5056 // element of the list to X.
5057 //
5058 // C++14 [over.ics.list]p3:
5059 // Otherwise, if the parameter type is "array of N X", if the initializer
5060 // list has exactly N elements or if it has fewer than N elements and X is
5061 // default-constructible, and if all the elements of the initializer list
5062 // can be implicitly converted to X, the implicit conversion sequence is
5063 // the worst conversion necessary to convert an element of the list to X.
5064 //
5065 // FIXME: We're missing a lot of these checks.
5066 bool toStdInitializerList = false;
5067 QualType X;
5068 if (ToType->isArrayType())
5069 X = S.Context.getAsArrayType(ToType)->getElementType();
5070 else
5071 toStdInitializerList = S.isStdInitializerList(ToType, &X);
5072 if (!X.isNull()) {
5073 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
5074 Expr *Init = From->getInit(i);
5075 ImplicitConversionSequence ICS =
5076 TryCopyInitialization(S, Init, X, SuppressUserConversions,
5077 InOverloadResolution,
5078 AllowObjCWritebackConversion);
5079 // If a single element isn't convertible, fail.
5080 if (ICS.isBad()) {
5081 Result = ICS;
5082 break;
5083 }
5084 // Otherwise, look for the worst conversion.
5085 if (Result.isBad() || CompareImplicitConversionSequences(
5086 S, From->getBeginLoc(), ICS, Result) ==
5087 ImplicitConversionSequence::Worse)
5088 Result = ICS;
5089 }
5090
5091 // For an empty list, we won't have computed any conversion sequence.
5092 // Introduce the identity conversion sequence.
5093 if (From->getNumInits() == 0) {
5094 Result.setStandard();
5095 Result.Standard.setAsIdentityConversion();
5096 Result.Standard.setFromType(ToType);
5097 Result.Standard.setAllToTypes(ToType);
5098 }
5099
5100 Result.setStdInitializerListElement(toStdInitializerList);
5101 return Result;
5102 }
5103
5104 // C++14 [over.ics.list]p4:
5105 // C++11 [over.ics.list]p3:
5106 // Otherwise, if the parameter is a non-aggregate class X and overload
5107 // resolution chooses a single best constructor [...] the implicit
5108 // conversion sequence is a user-defined conversion sequence. If multiple
5109 // constructors are viable but none is better than the others, the
5110 // implicit conversion sequence is a user-defined conversion sequence.
5111 if (ToType->isRecordType() && !ToType->isAggregateType()) {
5112 // This function can deal with initializer lists.
5113 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
5114 AllowedExplicit::None,
5115 InOverloadResolution, /*CStyle=*/false,
5116 AllowObjCWritebackConversion,
5117 /*AllowObjCConversionOnExplicit=*/false);
5118 }
5119
5120 // C++14 [over.ics.list]p5:
5121 // C++11 [over.ics.list]p4:
5122 // Otherwise, if the parameter has an aggregate type which can be
5123 // initialized from the initializer list [...] the implicit conversion
5124 // sequence is a user-defined conversion sequence.
5125 if (ToType->isAggregateType()) {
5126 // Type is an aggregate, argument is an init list. At this point it comes
5127 // down to checking whether the initialization works.
5128 // FIXME: Find out whether this parameter is consumed or not.
5129 InitializedEntity Entity =
5130 InitializedEntity::InitializeParameter(S.Context, ToType,
5131 /*Consumed=*/false);
5132 if (S.CanPerformAggregateInitializationForOverloadResolution(Entity,
5133 From)) {
5134 Result.setUserDefined();
5135 Result.UserDefined.Before.setAsIdentityConversion();
5136 // Initializer lists don't have a type.
5137 Result.UserDefined.Before.setFromType(QualType());
5138 Result.UserDefined.Before.setAllToTypes(QualType());
5139
5140 Result.UserDefined.After.setAsIdentityConversion();
5141 Result.UserDefined.After.setFromType(ToType);
5142 Result.UserDefined.After.setAllToTypes(ToType);
5143 Result.UserDefined.ConversionFunction = nullptr;
5144 }
5145 return Result;
5146 }
5147
5148 // C++14 [over.ics.list]p6:
5149 // C++11 [over.ics.list]p5:
5150 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
5151 if (ToType->isReferenceType()) {
5152 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
5153 // mention initializer lists in any way. So we go by what list-
5154 // initialization would do and try to extrapolate from that.
5155
5156 QualType T1 = ToType->castAs<ReferenceType>()->getPointeeType();
5157
5158 // If the initializer list has a single element that is reference-related
5159 // to the parameter type, we initialize the reference from that.
5160 if (From->getNumInits() == 1) {
5161 Expr *Init = From->getInit(0);
5162
5163 QualType T2 = Init->getType();
5164
5165 // If the initializer is the address of an overloaded function, try
5166 // to resolve the overloaded function. If all goes well, T2 is the
5167 // type of the resulting function.
5168 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
5169 DeclAccessPair Found;
5170 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
5171 Init, ToType, false, Found))
5172 T2 = Fn->getType();
5173 }
5174
5175 // Compute some basic properties of the types and the initializer.
5176 Sema::ReferenceCompareResult RefRelationship =
5177 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2);
5178
5179 if (RefRelationship >= Sema::Ref_Related) {
5180 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
5181 SuppressUserConversions,
5182 /*AllowExplicit=*/false);
5183 }
5184 }
5185
5186 // Otherwise, we bind the reference to a temporary created from the
5187 // initializer list.
5188 Result = TryListConversion(S, From, T1, SuppressUserConversions,
5189 InOverloadResolution,
5190 AllowObjCWritebackConversion);
5191 if (Result.isFailure())
5192 return Result;
5193 assert(!Result.isEllipsis() &&
5194 "Sub-initialization cannot result in ellipsis conversion.");
5195
5196 // Can we even bind to a temporary?
5197 if (ToType->isRValueReferenceType() ||
5198 (T1.isConstQualified() && !T1.isVolatileQualified())) {
5199 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
5200 Result.UserDefined.After;
5201 SCS.ReferenceBinding = true;
5202 SCS.IsLvalueReference = ToType->isLValueReferenceType();
5203 SCS.BindsToRvalue = true;
5204 SCS.BindsToFunctionLvalue = false;
5205 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
5206 SCS.ObjCLifetimeConversionBinding = false;
5207 } else
5208 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
5209 From, ToType);
5210 return Result;
5211 }
5212
5213 // C++14 [over.ics.list]p7:
5214 // C++11 [over.ics.list]p6:
5215 // Otherwise, if the parameter type is not a class:
5216 if (!ToType->isRecordType()) {
5217 // - if the initializer list has one element that is not itself an
5218 // initializer list, the implicit conversion sequence is the one
5219 // required to convert the element to the parameter type.
5220 unsigned NumInits = From->getNumInits();
5221 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
5222 Result = TryCopyInitialization(S, From->getInit(0), ToType,
5223 SuppressUserConversions,
5224 InOverloadResolution,
5225 AllowObjCWritebackConversion);
5226 // - if the initializer list has no elements, the implicit conversion
5227 // sequence is the identity conversion.
5228 else if (NumInits == 0) {
5229 Result.setStandard();
5230 Result.Standard.setAsIdentityConversion();
5231 Result.Standard.setFromType(ToType);
5232 Result.Standard.setAllToTypes(ToType);
5233 }
5234 return Result;
5235 }
5236
5237 // C++14 [over.ics.list]p8:
5238 // C++11 [over.ics.list]p7:
5239 // In all cases other than those enumerated above, no conversion is possible
5240 return Result;
5241}
5242
5243/// TryCopyInitialization - Try to copy-initialize a value of type
5244/// ToType from the expression From. Return the implicit conversion
5245/// sequence required to pass this argument, which may be a bad
5246/// conversion sequence (meaning that the argument cannot be passed to
5247/// a parameter of this type). If @p SuppressUserConversions, then we
5248/// do not permit any user-defined conversion sequences.
5249static ImplicitConversionSequence
5250TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5251 bool SuppressUserConversions,
5252 bool InOverloadResolution,
5253 bool AllowObjCWritebackConversion,
5254 bool AllowExplicit) {
5255 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5256 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5257 InOverloadResolution,AllowObjCWritebackConversion);
5258
5259 if (ToType->isReferenceType())
5260 return TryReferenceInit(S, From, ToType,
5261 /*FIXME:*/ From->getBeginLoc(),
5262 SuppressUserConversions, AllowExplicit);
5263
5264 return TryImplicitConversion(S, From, ToType,
5265 SuppressUserConversions,
5266 AllowedExplicit::None,
5267 InOverloadResolution,
5268 /*CStyle=*/false,
5269 AllowObjCWritebackConversion,
5270 /*AllowObjCConversionOnExplicit=*/false);
5271}
5272
5273static bool TryCopyInitialization(const CanQualType FromQTy,
5274 const CanQualType ToQTy,
5275 Sema &S,
5276 SourceLocation Loc,
5277 ExprValueKind FromVK) {
5278 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5279 ImplicitConversionSequence ICS =
5280 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5281
5282 return !ICS.isBad();
5283}
5284
5285/// TryObjectArgumentInitialization - Try to initialize the object
5286/// parameter of the given member function (@c Method) from the
5287/// expression @p From.
5288static ImplicitConversionSequence
5289TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5290 Expr::Classification FromClassification,
5291 CXXMethodDecl *Method,
5292 CXXRecordDecl *ActingContext) {
5293 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5294 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5295 // const volatile object.
5296 Qualifiers Quals = Method->getMethodQualifiers();
5297 if (isa<CXXDestructorDecl>(Method)) {
5298 Quals.addConst();
5299 Quals.addVolatile();
5300 }
5301
5302 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5303
5304 // Set up the conversion sequence as a "bad" conversion, to allow us
5305 // to exit early.
5306 ImplicitConversionSequence ICS;
5307
5308 // We need to have an object of class type.
5309 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5310 FromType = PT->getPointeeType();
5311
5312 // When we had a pointer, it's implicitly dereferenced, so we
5313 // better have an lvalue.
5314 assert(FromClassification.isLValue());
5315 }
5316
5317 assert(FromType->isRecordType());
5318
5319 // C++0x [over.match.funcs]p4:
5320 // For non-static member functions, the type of the implicit object
5321 // parameter is
5322 //
5323 // - "lvalue reference to cv X" for functions declared without a
5324 // ref-qualifier or with the & ref-qualifier
5325 // - "rvalue reference to cv X" for functions declared with the &&
5326 // ref-qualifier
5327 //
5328 // where X is the class of which the function is a member and cv is the
5329 // cv-qualification on the member function declaration.
5330 //
5331 // However, when finding an implicit conversion sequence for the argument, we
5332 // are not allowed to perform user-defined conversions
5333 // (C++ [over.match.funcs]p5). We perform a simplified version of
5334 // reference binding here, that allows class rvalues to bind to
5335 // non-constant references.
5336
5337 // First check the qualifiers.
5338 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5339 if (ImplicitParamType.getCVRQualifiers()
5340 != FromTypeCanon.getLocalCVRQualifiers() &&
5341 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5342 ICS.setBad(BadConversionSequence::bad_qualifiers,
5343 FromType, ImplicitParamType);
5344 return ICS;
5345 }
5346
5347 if (FromTypeCanon.hasAddressSpace()) {
5348 Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers();
5349 Qualifiers QualsFromType = FromTypeCanon.getQualifiers();
5350 if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) {
5351 ICS.setBad(BadConversionSequence::bad_qualifiers,
5352 FromType, ImplicitParamType);
5353 return ICS;
5354 }
5355 }
5356
5357 // Check that we have either the same type or a derived type. It
5358 // affects the conversion rank.
5359 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5360 ImplicitConversionKind SecondKind;
5361 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5362 SecondKind = ICK_Identity;
5363 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5364 SecondKind = ICK_Derived_To_Base;
5365 else {
5366 ICS.setBad(BadConversionSequence::unrelated_class,
5367 FromType, ImplicitParamType);
5368 return ICS;
5369 }
5370
5371 // Check the ref-qualifier.
5372 switch (Method->getRefQualifier()) {
5373 case RQ_None:
5374 // Do nothing; we don't care about lvalueness or rvalueness.
5375 break;
5376
5377 case RQ_LValue:
5378 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5379 // non-const lvalue reference cannot bind to an rvalue
5380 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5381 ImplicitParamType);
5382 return ICS;
5383 }
5384 break;
5385
5386 case RQ_RValue:
5387 if (!FromClassification.isRValue()) {
5388 // rvalue reference cannot bind to an lvalue
5389 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5390 ImplicitParamType);
5391 return ICS;
5392 }
5393 break;
5394 }
5395
5396 // Success. Mark this as a reference binding.
5397 ICS.setStandard();
5398 ICS.Standard.setAsIdentityConversion();
5399 ICS.Standard.Second = SecondKind;
5400 ICS.Standard.setFromType(FromType);
5401 ICS.Standard.setAllToTypes(ImplicitParamType);
5402 ICS.Standard.ReferenceBinding = true;
5403 ICS.Standard.DirectBinding = true;
5404 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5405 ICS.Standard.BindsToFunctionLvalue = false;
5406 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5407 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5408 = (Method->getRefQualifier() == RQ_None);
5409 return ICS;
5410}
5411
5412/// PerformObjectArgumentInitialization - Perform initialization of
5413/// the implicit object parameter for the given Method with the given
5414/// expression.
5415ExprResult
5416Sema::PerformObjectArgumentInitialization(Expr *From,
5417 NestedNameSpecifier *Qualifier,
5418 NamedDecl *FoundDecl,
5419 CXXMethodDecl *Method) {
5420 QualType FromRecordType, DestType;
5421 QualType ImplicitParamRecordType =
5422 Method->getThisType()->castAs<PointerType>()->getPointeeType();
5423
5424 Expr::Classification FromClassification;
5425 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5426 FromRecordType = PT->getPointeeType();
5427 DestType = Method->getThisType();
5428 FromClassification = Expr::Classification::makeSimpleLValue();
5429 } else {
5430 FromRecordType = From->getType();
5431 DestType = ImplicitParamRecordType;
5432 FromClassification = From->Classify(Context);
5433
5434 // When performing member access on an rvalue, materialize a temporary.
5435 if (From->isRValue()) {
5436 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5437 Method->getRefQualifier() !=
5438 RefQualifierKind::RQ_RValue);
5439 }
5440 }
5441
5442 // Note that we always use the true parent context when performing
5443 // the actual argument initialization.
5444 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5445 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5446 Method->getParent());
5447 if (ICS.isBad()) {
5448 switch (ICS.Bad.Kind) {
5449 case BadConversionSequence::bad_qualifiers: {
5450 Qualifiers FromQs = FromRecordType.getQualifiers();
5451 Qualifiers ToQs = DestType.getQualifiers();
5452 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5453 if (CVR) {
5454 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5455 << Method->getDeclName() << FromRecordType << (CVR - 1)
5456 << From->getSourceRange();
5457 Diag(Method->getLocation(), diag::note_previous_decl)
5458 << Method->getDeclName();
5459 return ExprError();
5460 }
5461 break;
5462 }
5463
5464 case BadConversionSequence::lvalue_ref_to_rvalue:
5465 case BadConversionSequence::rvalue_ref_to_lvalue: {
5466 bool IsRValueQualified =
5467 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5468 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5469 << Method->getDeclName() << FromClassification.isRValue()
5470 << IsRValueQualified;
5471 Diag(Method->getLocation(), diag::note_previous_decl)
5472 << Method->getDeclName();
5473 return ExprError();
5474 }
5475
5476 case BadConversionSequence::no_conversion:
5477 case BadConversionSequence::unrelated_class:
5478 break;
5479 }
5480
5481 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5482 << ImplicitParamRecordType << FromRecordType
5483 << From->getSourceRange();
5484 }
5485
5486 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5487 ExprResult FromRes =
5488 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5489 if (FromRes.isInvalid())
5490 return ExprError();
5491 From = FromRes.get();
5492 }
5493
5494 if (!Context.hasSameType(From->getType(), DestType)) {
5495 CastKind CK;
5496 QualType PteeTy = DestType->getPointeeType();
5497 LangAS DestAS =
5498 PteeTy.isNull() ? DestType.getAddressSpace() : PteeTy.getAddressSpace();
5499 if (FromRecordType.getAddressSpace() != DestAS)
5500 CK = CK_AddressSpaceConversion;
5501 else
5502 CK = CK_NoOp;
5503 From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get();
5504 }
5505 return From;
5506}
5507
5508/// TryContextuallyConvertToBool - Attempt to contextually convert the
5509/// expression From to bool (C++0x [conv]p3).
5510static ImplicitConversionSequence
5511TryContextuallyConvertToBool(Sema &S, Expr *From) {
5512 // C++ [dcl.init]/17.8:
5513 // - Otherwise, if the initialization is direct-initialization, the source
5514 // type is std::nullptr_t, and the destination type is bool, the initial
5515 // value of the object being initialized is false.
5516 if (From->getType()->isNullPtrType())
5517 return ImplicitConversionSequence::getNullptrToBool(From->getType(),
5518 S.Context.BoolTy,
5519 From->isGLValue());
5520
5521 // All other direct-initialization of bool is equivalent to an implicit
5522 // conversion to bool in which explicit conversions are permitted.
5523 return TryImplicitConversion(S, From, S.Context.BoolTy,
5524 /*SuppressUserConversions=*/false,
5525 AllowedExplicit::Conversions,
5526 /*InOverloadResolution=*/false,
5527 /*CStyle=*/false,
5528 /*AllowObjCWritebackConversion=*/false,
5529 /*AllowObjCConversionOnExplicit=*/false);
5530}
5531
5532/// PerformContextuallyConvertToBool - Perform a contextual conversion
5533/// of the expression From to bool (C++0x [conv]p3).
5534ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5535 if (checkPlaceholderForOverload(*this, From))
5536 return ExprError();
5537
5538 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5539 if (!ICS.isBad())
5540 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5541
5542 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5543 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5544 << From->getType() << From->getSourceRange();
5545 return ExprError();
5546}
5547
5548/// Check that the specified conversion is permitted in a converted constant
5549/// expression, according to C++11 [expr.const]p3. Return true if the conversion
5550/// is acceptable.
5551static bool CheckConvertedConstantConversions(Sema &S,
5552 StandardConversionSequence &SCS) {
5553 // Since we know that the target type is an integral or unscoped enumeration
5554 // type, most conversion kinds are impossible. All possible First and Third
5555 // conversions are fine.
5556 switch (SCS.Second) {
5557 case ICK_Identity:
5558 case ICK_Integral_Promotion:
5559 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5560 case ICK_Zero_Queue_Conversion:
5561 return true;
5562
5563 case ICK_Boolean_Conversion:
5564 // Conversion from an integral or unscoped enumeration type to bool is
5565 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5566 // conversion, so we allow it in a converted constant expression.
5567 //
5568 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5569 // a lot of popular code. We should at least add a warning for this
5570 // (non-conforming) extension.
5571 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5572 SCS.getToType(2)->isBooleanType();
5573
5574 case ICK_Pointer_Conversion:
5575 case ICK_Pointer_Member:
5576 // C++1z: null pointer conversions and null member pointer conversions are
5577 // only permitted if the source type is std::nullptr_t.
5578 return SCS.getFromType()->isNullPtrType();
5579
5580 case ICK_Floating_Promotion:
5581 case ICK_Complex_Promotion:
5582 case ICK_Floating_Conversion:
5583 case ICK_Complex_Conversion:
5584 case ICK_Floating_Integral:
5585 case ICK_Compatible_Conversion:
5586 case ICK_Derived_To_Base:
5587 case ICK_Vector_Conversion:
5588 case ICK_SVE_Vector_Conversion:
5589 case ICK_Vector_Splat:
5590 case ICK_Complex_Real:
5591 case ICK_Block_Pointer_Conversion:
5592 case ICK_TransparentUnionConversion:
5593 case ICK_Writeback_Conversion:
5594 case ICK_Zero_Event_Conversion:
5595 case ICK_C_Only_Conversion:
5596 case ICK_Incompatible_Pointer_Conversion:
5597 return false;
5598
5599 case ICK_Lvalue_To_Rvalue:
5600 case ICK_Array_To_Pointer:
5601 case ICK_Function_To_Pointer:
5602 llvm_unreachable("found a first conversion kind in Second");
5603
5604 case ICK_Function_Conversion:
5605 case ICK_Qualification:
5606 llvm_unreachable("found a third conversion kind in Second");
5607
5608 case ICK_Num_Conversion_Kinds:
5609 break;
5610 }
5611
5612 llvm_unreachable("unknown conversion kind");
5613}
5614
5615/// CheckConvertedConstantExpression - Check that the expression From is a
5616/// converted constant expression of type T, perform the conversion and produce
5617/// the converted expression, per C++11 [expr.const]p3.
5618static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5619 QualType T, APValue &Value,
5620 Sema::CCEKind CCE,
5621 bool RequireInt,
5622 NamedDecl *Dest) {
5623 assert(S.getLangOpts().CPlusPlus11 &&
5624 "converted constant expression outside C++11");
5625
5626 if (checkPlaceholderForOverload(S, From))
5627 return ExprError();
5628
5629 // C++1z [expr.const]p3:
5630 // A converted constant expression of type T is an expression,
5631 // implicitly converted to type T, where the converted
5632 // expression is a constant expression and the implicit conversion
5633 // sequence contains only [... list of conversions ...].
5634 // C++1z [stmt.if]p2:
5635 // If the if statement is of the form if constexpr, the value of the
5636 // condition shall be a contextually converted constant expression of type
5637 // bool.
5638 ImplicitConversionSequence ICS =
5639 CCE == Sema::CCEK_ConstexprIf || CCE == Sema::CCEK_ExplicitBool
5640 ? TryContextuallyConvertToBool(S, From)
5641 : TryCopyInitialization(S, From, T,
5642 /*SuppressUserConversions=*/false,
5643 /*InOverloadResolution=*/false,
5644 /*AllowObjCWritebackConversion=*/false,
5645 /*AllowExplicit=*/false);
5646 StandardConversionSequence *SCS = nullptr;
5647 switch (ICS.getKind()) {
5648 case ImplicitConversionSequence::StandardConversion:
5649 SCS = &ICS.Standard;
5650 break;
5651 case ImplicitConversionSequence::UserDefinedConversion:
5652 if (T->isRecordType())
5653 SCS = &ICS.UserDefined.Before;
5654 else
5655 SCS = &ICS.UserDefined.After;
5656 break;
5657 case ImplicitConversionSequence::AmbiguousConversion:
5658 case ImplicitConversionSequence::BadConversion:
5659 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5660 return S.Diag(From->getBeginLoc(),
5661 diag::err_typecheck_converted_constant_expression)
5662 << From->getType() << From->getSourceRange() << T;
5663 return ExprError();
5664
5665 case ImplicitConversionSequence::EllipsisConversion:
5666 llvm_unreachable("ellipsis conversion in converted constant expression");
5667 }
5668
5669 // Check that we would only use permitted conversions.
5670 if (!CheckConvertedConstantConversions(S, *SCS)) {
5671 return S.Diag(From->getBeginLoc(),
5672 diag::err_typecheck_converted_constant_expression_disallowed)
5673 << From->getType() << From->getSourceRange() << T;
5674 }
5675 // [...] and where the reference binding (if any) binds directly.
5676 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5677 return S.Diag(From->getBeginLoc(),
5678 diag::err_typecheck_converted_constant_expression_indirect)
5679 << From->getType() << From->getSourceRange() << T;
5680 }
5681
5682 // Usually we can simply apply the ImplicitConversionSequence we formed
5683 // earlier, but that's not guaranteed to work when initializing an object of
5684 // class type.
5685 ExprResult Result;
5686 if (T->isRecordType()) {
5687 assert(CCE == Sema::CCEK_TemplateArg &&
5688 "unexpected class type converted constant expr");
5689 Result = S.PerformCopyInitialization(
5690 InitializedEntity::InitializeTemplateParameter(
5691 T, cast<NonTypeTemplateParmDecl>(Dest)),
5692 SourceLocation(), From);
5693 } else {
5694 Result = S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5695 }
5696 if (Result.isInvalid())
5697 return Result;
5698
5699 // C++2a [intro.execution]p5:
5700 // A full-expression is [...] a constant-expression [...]
5701 Result =
5702 S.ActOnFinishFullExpr(Result.get(), From->getExprLoc(),
5703 /*DiscardedValue=*/false, /*IsConstexpr=*/true);
5704 if (Result.isInvalid())
5705 return Result;
5706
5707 // Check for a narrowing implicit conversion.
5708 bool ReturnPreNarrowingValue = false;
5709 APValue PreNarrowingValue;
5710 QualType PreNarrowingType;
5711 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5712 PreNarrowingType)) {
5713 case NK_Dependent_Narrowing:
5714 // Implicit conversion to a narrower type, but the expression is
5715 // value-dependent so we can't tell whether it's actually narrowing.
5716 case NK_Variable_Narrowing:
5717 // Implicit conversion to a narrower type, and the value is not a constant
5718 // expression. We'll diagnose this in a moment.
5719 case NK_Not_Narrowing:
5720 break;
5721
5722 case NK_Constant_Narrowing:
5723 if (CCE == Sema::CCEK_ArrayBound &&
5724 PreNarrowingType->isIntegralOrEnumerationType() &&
5725 PreNarrowingValue.isInt()) {
5726 // Don't diagnose array bound narrowing here; we produce more precise
5727 // errors by allowing the un-narrowed value through.
5728 ReturnPreNarrowingValue = true;
5729 break;
5730 }
5731 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5732 << CCE << /*Constant*/ 1
5733 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5734 break;
5735
5736 case NK_Type_Narrowing:
5737 // FIXME: It would be better to diagnose that the expression is not a
5738 // constant expression.
5739 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5740 << CCE << /*Constant*/ 0 << From->getType() << T;
5741 break;
5742 }
5743
5744 if (Result.get()->isValueDependent()) {
5745 Value = APValue();
5746 return Result;
5747 }
5748
5749 // Check the expression is a constant expression.
5750 SmallVector<PartialDiagnosticAt, 8> Notes;
5751 Expr::EvalResult Eval;
5752 Eval.Diag = &Notes;
5753
5754 ConstantExprKind Kind;
5755 if (CCE == Sema::CCEK_TemplateArg && T->isRecordType())
5756 Kind = ConstantExprKind::ClassTemplateArgument;
5757 else if (CCE == Sema::CCEK_TemplateArg)
5758 Kind = ConstantExprKind::NonClassTemplateArgument;
5759 else
5760 Kind = ConstantExprKind::Normal;
5761
5762 if (!Result.get()->EvaluateAsConstantExpr(Eval, S.Context, Kind) ||
5763 (RequireInt && !Eval.Val.isInt())) {
5764 // The expression can't be folded, so we can't keep it at this position in
5765 // the AST.
5766 Result = ExprError();
5767 } else {
5768 Value = Eval.Val;
5769
5770 if (Notes.empty()) {
5771 // It's a constant expression.
5772 Expr *E = ConstantExpr::Create(S.Context, Result.get(), Value);
5773 if (ReturnPreNarrowingValue)
5774 Value = std::move(PreNarrowingValue);
5775 return E;
5776 }
5777 }
5778
5779 // It's not a constant expression. Produce an appropriate diagnostic.
5780 if (Notes.size() == 1 &&
5781 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) {
5782 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5783 } else if (!Notes.empty() && Notes[0].second.getDiagID() ==
5784 diag::note_constexpr_invalid_template_arg) {
5785 Notes[0].second.setDiagID(diag::err_constexpr_invalid_template_arg);
5786 for (unsigned I = 0; I < Notes.size(); ++I)
5787 S.Diag(Notes[I].first, Notes[I].second);
5788 } else {
5789 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5790 << CCE << From->getSourceRange();
5791 for (unsigned I = 0; I < Notes.size(); ++I)
5792 S.Diag(Notes[I].first, Notes[I].second);
5793 }
5794 return ExprError();
5795}
5796
5797ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5798 APValue &Value, CCEKind CCE,
5799 NamedDecl *Dest) {
5800 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false,
5801 Dest);
5802}
5803
5804ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5805 llvm::APSInt &Value,
5806 CCEKind CCE) {
5807 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5808
5809 APValue V;
5810 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true,
5811 /*Dest=*/nullptr);
5812 if (!R.isInvalid() && !R.get()->isValueDependent())
5813 Value = V.getInt();
5814 return R;
5815}
5816
5817
5818/// dropPointerConversions - If the given standard conversion sequence
5819/// involves any pointer conversions, remove them. This may change
5820/// the result type of the conversion sequence.
5821static void dropPointerConversion(StandardConversionSequence &SCS) {
5822 if (SCS.Second == ICK_Pointer_Conversion) {
5823 SCS.Second = ICK_Identity;
5824 SCS.Third = ICK_Identity;
5825 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5826 }
5827}
5828
5829/// TryContextuallyConvertToObjCPointer - Attempt to contextually
5830/// convert the expression From to an Objective-C pointer type.
5831static ImplicitConversionSequence
5832TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5833 // Do an implicit conversion to 'id'.
5834 QualType Ty = S.Context.getObjCIdType();
5835 ImplicitConversionSequence ICS
5836 = TryImplicitConversion(S, From, Ty,
5837 // FIXME: Are these flags correct?
5838 /*SuppressUserConversions=*/false,
5839 AllowedExplicit::Conversions,
5840 /*InOverloadResolution=*/false,
5841 /*CStyle=*/false,
5842 /*AllowObjCWritebackConversion=*/false,
5843 /*AllowObjCConversionOnExplicit=*/true);
5844
5845 // Strip off any final conversions to 'id'.
5846 switch (ICS.getKind()) {
5847 case ImplicitConversionSequence::BadConversion:
5848 case ImplicitConversionSequence::AmbiguousConversion:
5849 case ImplicitConversionSequence::EllipsisConversion:
5850 break;
5851
5852 case ImplicitConversionSequence::UserDefinedConversion:
5853 dropPointerConversion(ICS.UserDefined.After);
5854 break;
5855
5856 case ImplicitConversionSequence::StandardConversion:
5857 dropPointerConversion(ICS.Standard);
5858 break;
5859 }
5860
5861 return ICS;
5862}
5863
5864/// PerformContextuallyConvertToObjCPointer - Perform a contextual
5865/// conversion of the expression From to an Objective-C pointer type.
5866/// Returns a valid but null ExprResult if no conversion sequence exists.
5867ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5868 if (checkPlaceholderForOverload(*this, From))
5869 return ExprError();
5870
5871 QualType Ty = Context.getObjCIdType();
5872 ImplicitConversionSequence ICS =
5873 TryContextuallyConvertToObjCPointer(*this, From);
5874 if (!ICS.isBad())
5875 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5876 return ExprResult();
5877}
5878
5879/// Determine whether the provided type is an integral type, or an enumeration
5880/// type of a permitted flavor.
5881bool Sema::ICEConvertDiagnoser::match(QualType T) {
5882 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5883 : T->isIntegralOrUnscopedEnumerationType();
5884}
5885
5886static ExprResult
5887diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5888 Sema::ContextualImplicitConverter &Converter,
5889 QualType T, UnresolvedSetImpl &ViableConversions) {
5890
5891 if (Converter.Suppress)
5892 return ExprError();
5893
5894 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5895 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5896 CXXConversionDecl *Conv =
5897 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5898 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5899 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5900 }
5901 return From;
5902}
5903
5904static bool
5905diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5906 Sema::ContextualImplicitConverter &Converter,
5907 QualType T, bool HadMultipleCandidates,
5908 UnresolvedSetImpl &ExplicitConversions) {
5909 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5910 DeclAccessPair Found = ExplicitConversions[0];
5911 CXXConversionDecl *Conversion =
5912 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5913
5914 // The user probably meant to invoke the given explicit
5915 // conversion; use it.
5916 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5917 std::string TypeStr;
5918 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5919
5920 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5921 << FixItHint::CreateInsertion(From->getBeginLoc(),
5922 "static_cast<" + TypeStr + ">(")
5923 << FixItHint::CreateInsertion(
5924 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5925 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5926
5927 // If we aren't in a SFINAE context, build a call to the
5928 // explicit conversion function.
5929 if (SemaRef.isSFINAEContext())
5930 return true;
5931
5932 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5933 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5934 HadMultipleCandidates);
5935 if (Result.isInvalid())
5936 return true;
5937 // Record usage of conversion in an implicit cast.
5938 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5939 CK_UserDefinedConversion, Result.get(),
5940 nullptr, Result.get()->getValueKind(),
5941 SemaRef.CurFPFeatureOverrides());
5942 }
5943 return false;
5944}
5945
5946static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5947 Sema::ContextualImplicitConverter &Converter,
5948 QualType T, bool HadMultipleCandidates,
5949 DeclAccessPair &Found) {
5950 CXXConversionDecl *Conversion =
5951 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5952 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5953
5954 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5955 if (!Converter.SuppressConversion) {
5956 if (SemaRef.isSFINAEContext())
5957 return true;
5958
5959 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5960 << From->getSourceRange();
5961 }
5962
5963 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5964 HadMultipleCandidates);
5965 if (Result.isInvalid())
5966 return true;
5967 // Record usage of conversion in an implicit cast.
5968 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5969 CK_UserDefinedConversion, Result.get(),
5970 nullptr, Result.get()->getValueKind(),
5971 SemaRef.CurFPFeatureOverrides());
5972 return false;
5973}
5974
5975static ExprResult finishContextualImplicitConversion(
5976 Sema &SemaRef, SourceLocation Loc, Expr *From,
5977 Sema::ContextualImplicitConverter &Converter) {
5978 if (!Converter.match(From->getType()) && !Converter.Suppress)
5979 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5980 << From->getSourceRange();
5981
5982 return SemaRef.DefaultLvalueConversion(From);
5983}
5984
5985static void
5986collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5987 UnresolvedSetImpl &ViableConversions,
5988 OverloadCandidateSet &CandidateSet) {
5989 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5990 DeclAccessPair FoundDecl = ViableConversions[I];
5991 NamedDecl *D = FoundDecl.getDecl();
5992 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5993 if (isa<UsingShadowDecl>(D))
5994 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5995
5996 CXXConversionDecl *Conv;
5997 FunctionTemplateDecl *ConvTemplate;
5998 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5999 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
6000 else
6001 Conv = cast<CXXConversionDecl>(D);
6002
6003 if (ConvTemplate)
6004 SemaRef.AddTemplateConversionCandidate(
6005 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
6006 /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true);
6007 else
6008 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
6009 ToType, CandidateSet,
6010 /*AllowObjCConversionOnExplicit=*/false,
6011 /*AllowExplicit*/ true);
6012 }
6013}
6014
6015/// Attempt to convert the given expression to a type which is accepted
6016/// by the given converter.
6017///
6018/// This routine will attempt to convert an expression of class type to a
6019/// type accepted by the specified converter. In C++11 and before, the class
6020/// must have a single non-explicit conversion function converting to a matching
6021/// type. In C++1y, there can be multiple such conversion functions, but only
6022/// one target type.
6023///
6024/// \param Loc The source location of the construct that requires the
6025/// conversion.
6026///
6027/// \param From The expression we're converting from.
6028///
6029/// \param Converter Used to control and diagnose the conversion process.
6030///
6031/// \returns The expression, converted to an integral or enumeration type if
6032/// successful.
6033ExprResult Sema::PerformContextualImplicitConversion(
6034 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
6035 // We can't perform any more checking for type-dependent expressions.
6036 if (From->isTypeDependent())
6037 return From;
6038
6039 // Process placeholders immediately.
6040 if (From->hasPlaceholderType()) {
6041 ExprResult result = CheckPlaceholderExpr(From);
6042 if (result.isInvalid())
6043 return result;
6044 From = result.get();
6045 }
6046
6047 // If the expression already has a matching type, we're golden.
6048 QualType T = From->getType();
6049 if (Converter.match(T))
6050 return DefaultLvalueConversion(From);
6051
6052 // FIXME: Check for missing '()' if T is a function type?
6053
6054 // We can only perform contextual implicit conversions on objects of class
6055 // type.
6056 const RecordType *RecordTy = T->getAs<RecordType>();
6057 if (!RecordTy || !getLangOpts().CPlusPlus) {
6058 if (!Converter.Suppress)
6059 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
6060 return From;
6061 }
6062
6063 // We must have a complete class type.
6064 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
6065 ContextualImplicitConverter &Converter;
6066 Expr *From;
6067
6068 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
6069 : Converter(Converter), From(From) {}
6070
6071 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
6072 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
6073 }
6074 } IncompleteDiagnoser(Converter, From);
6075
6076 if (Converter.Suppress ? !isCompleteType(Loc, T)
6077 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
6078 return From;
6079
6080 // Look for a conversion to an integral or enumeration type.
6081 UnresolvedSet<4>
6082 ViableConversions; // These are *potentially* viable in C++1y.
6083 UnresolvedSet<4> ExplicitConversions;
6084 const auto &Conversions =
6085 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
6086
6087 bool HadMultipleCandidates =
6088 (std::distance(Conversions.begin(), Conversions.end()) > 1);
6089
6090 // To check that there is only one target type, in C++1y:
6091 QualType ToType;
6092 bool HasUniqueTargetType = true;
6093
6094 // Collect explicit or viable (potentially in C++1y) conversions.
6095 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
6096 NamedDecl *D = (*I)->getUnderlyingDecl();
6097 CXXConversionDecl *Conversion;
6098 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
6099 if (ConvTemplate) {
6100 if (getLangOpts().CPlusPlus14)
6101 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
6102 else
6103 continue; // C++11 does not consider conversion operator templates(?).
6104 } else
6105 Conversion = cast<CXXConversionDecl>(D);
6106
6107 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
6108 "Conversion operator templates are considered potentially "
6109 "viable in C++1y");
6110
6111 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
6112 if (Converter.match(CurToType) || ConvTemplate) {
6113
6114 if (Conversion->isExplicit()) {
6115 // FIXME: For C++1y, do we need this restriction?
6116 // cf. diagnoseNoViableConversion()
6117 if (!ConvTemplate)
6118 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
6119 } else {
6120 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
6121 if (ToType.isNull())
6122 ToType = CurToType.getUnqualifiedType();
6123 else if (HasUniqueTargetType &&
6124 (CurToType.getUnqualifiedType() != ToType))
6125 HasUniqueTargetType = false;
6126 }
6127 ViableConversions.addDecl(I.getDecl(), I.getAccess());
6128 }
6129 }
6130 }
6131
6132 if (getLangOpts().CPlusPlus14) {
6133 // C++1y [conv]p6:
6134 // ... An expression e of class type E appearing in such a context
6135 // is said to be contextually implicitly converted to a specified
6136 // type T and is well-formed if and only if e can be implicitly
6137 // converted to a type T that is determined as follows: E is searched
6138 // for conversion functions whose return type is cv T or reference to
6139 // cv T such that T is allowed by the context. There shall be
6140 // exactly one such T.
6141
6142 // If no unique T is found:
6143 if (ToType.isNull()) {
6144 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6145 HadMultipleCandidates,
6146 ExplicitConversions))
6147 return ExprError();
6148 return finishContextualImplicitConversion(*this, Loc, From, Converter);
6149 }
6150
6151 // If more than one unique Ts are found:
6152 if (!HasUniqueTargetType)
6153 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6154 ViableConversions);
6155
6156 // If one unique T is found:
6157 // First, build a candidate set from the previously recorded
6158 // potentially viable conversions.
6159 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6160 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
6161 CandidateSet);
6162
6163 // Then, perform overload resolution over the candidate set.
6164 OverloadCandidateSet::iterator Best;
6165 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
6166 case OR_Success: {
6167 // Apply this conversion.
6168 DeclAccessPair Found =
6169 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
6170 if (recordConversion(*this, Loc, From, Converter, T,
6171 HadMultipleCandidates, Found))
6172 return ExprError();
6173 break;
6174 }
6175 case OR_Ambiguous:
6176 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6177 ViableConversions);
6178 case OR_No_Viable_Function:
6179 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6180 HadMultipleCandidates,
6181 ExplicitConversions))
6182 return ExprError();
6183 LLVM_FALLTHROUGH;
6184 case OR_Deleted:
6185 // We'll complain below about a non-integral condition type.
6186 break;
6187 }
6188 } else {
6189 switch (ViableConversions.size()) {
6190 case 0: {
6191 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6192 HadMultipleCandidates,
6193 ExplicitConversions))
6194 return ExprError();
6195
6196 // We'll complain below about a non-integral condition type.
6197 break;
6198 }
6199 case 1: {
6200 // Apply this conversion.
6201 DeclAccessPair Found = ViableConversions[0];
6202 if (recordConversion(*this, Loc, From, Converter, T,
6203 HadMultipleCandidates, Found))
6204 return ExprError();
6205 break;
6206 }
6207 default:
6208 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6209 ViableConversions);
6210 }
6211 }
6212
6213 return finishContextualImplicitConversion(*this, Loc, From, Converter);
6214}
6215
6216/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
6217/// an acceptable non-member overloaded operator for a call whose
6218/// arguments have types T1 (and, if non-empty, T2). This routine
6219/// implements the check in C++ [over.match.oper]p3b2 concerning
6220/// enumeration types.
6221static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
6222 FunctionDecl *Fn,
6223 ArrayRef<Expr *> Args) {
6224 QualType T1 = Args[0]->getType();
6225 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
6226
6227 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
6228 return true;
6229
6230 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
6231 return true;
6232
6233 const auto *Proto = Fn->getType()->castAs<FunctionProtoType>();
6234 if (Proto->getNumParams() < 1)
6235 return false;
6236
6237 if (T1->isEnumeralType()) {
6238 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
6239 if (Context.hasSameUnqualifiedType(T1, ArgType))
6240 return true;
6241 }
6242
6243 if (Proto->getNumParams() < 2)
6244 return false;
6245
6246 if (!T2.isNull() && T2->isEnumeralType()) {
6247 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
6248 if (Context.hasSameUnqualifiedType(T2, ArgType))
6249 return true;
6250 }
6251
6252 return false;
6253}
6254
6255/// AddOverloadCandidate - Adds the given function to the set of
6256/// candidate functions, using the given function call arguments. If
6257/// @p SuppressUserConversions, then don't allow user-defined
6258/// conversions via constructors or conversion operators.
6259///
6260/// \param PartialOverloading true if we are performing "partial" overloading
6261/// based on an incomplete set of function arguments. This feature is used by
6262/// code completion.
6263void Sema::AddOverloadCandidate(
6264 FunctionDecl *Function, DeclAccessPair FoundDecl, ArrayRef<Expr *> Args,
6265 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6266 bool PartialOverloading, bool AllowExplicit, bool AllowExplicitConversions,
6267 ADLCallKind IsADLCandidate, ConversionSequenceList EarlyConversions,
6268 OverloadCandidateParamOrder PO) {
6269 const FunctionProtoType *Proto
6270 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
6271 assert(Proto && "Functions without a prototype cannot be overloaded");
6272 assert(!Function->getDescribedFunctionTemplate() &&
6273 "Use AddTemplateOverloadCandidate for function templates");
6274
6275 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
6276 if (!isa<CXXConstructorDecl>(Method)) {
6277 // If we get here, it's because we're calling a member function
6278 // that is named without a member access expression (e.g.,
6279 // "this->f") that was either written explicitly or created
6280 // implicitly. This can happen with a qualified call to a member
6281 // function, e.g., X::f(). We use an empty type for the implied
6282 // object argument (C++ [over.call.func]p3), and the acting context
6283 // is irrelevant.
6284 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
6285 Expr::Classification::makeSimpleLValue(), Args,
6286 CandidateSet, SuppressUserConversions,
6287 PartialOverloading, EarlyConversions, PO);
6288 return;
6289 }
6290 // We treat a constructor like a non-member function, since its object
6291 // argument doesn't participate in overload resolution.
6292 }
6293
6294 if (!CandidateSet.isNewCandidate(Function, PO))
6295 return;
6296
6297 // C++11 [class.copy]p11: [DR1402]
6298 // A defaulted move constructor that is defined as deleted is ignored by
6299 // overload resolution.
6300 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
6301 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
6302 Constructor->isMoveConstructor())
6303 return;
6304
6305 // Overload resolution is always an unevaluated context.
6306 EnterExpressionEvaluationContext Unevaluated(
6307 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6308
6309 // C++ [over.match.oper]p3:
6310 // if no operand has a class type, only those non-member functions in the
6311 // lookup set that have a first parameter of type T1 or "reference to
6312 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
6313 // is a right operand) a second parameter of type T2 or "reference to
6314 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
6315 // candidate functions.
6316 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
6317 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
6318 return;
6319
6320 // Add this candidate
6321 OverloadCandidate &Candidate =
6322 CandidateSet.addCandidate(Args.size(), EarlyConversions);
6323 Candidate.FoundDecl = FoundDecl;
6324 Candidate.Function = Function;
6325 Candidate.Viable = true;
6326 Candidate.RewriteKind =
6327 CandidateSet.getRewriteInfo().getRewriteKind(Function, PO);
6328 Candidate.IsSurrogate = false;
6329 Candidate.IsADLCandidate = IsADLCandidate;
6330 Candidate.IgnoreObjectArgument = false;
6331 Candidate.ExplicitCallArguments = Args.size();
6332
6333 // Explicit functions are not actually candidates at all if we're not
6334 // allowing them in this context, but keep them around so we can point
6335 // to them in diagnostics.
6336 if (!AllowExplicit && ExplicitSpecifier::getFromDecl(Function).isExplicit()) {
6337 Candidate.Viable = false;
6338 Candidate.FailureKind = ovl_fail_explicit;
6339 return;
6340 }
6341
6342 if (Function->isMultiVersion() && Function->hasAttr<TargetAttr>() &&
6343 !Function->getAttr<TargetAttr>()->isDefaultVersion()) {
6344 Candidate.Viable = false;
6345 Candidate.FailureKind = ovl_non_default_multiversion_function;
6346 return;
6347 }
6348
6349 if (Constructor) {
6350 // C++ [class.copy]p3:
6351 // A member function template is never instantiated to perform the copy
6352 // of a class object to an object of its class type.
6353 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
6354 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
6355 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
6356 IsDerivedFrom(Args[0]->getBeginLoc(), Args[0]->getType(),
6357 ClassType))) {
6358 Candidate.Viable = false;
6359 Candidate.FailureKind = ovl_fail_illegal_constructor;
6360 return;
6361 }
6362
6363 // C++ [over.match.funcs]p8: (proposed DR resolution)
6364 // A constructor inherited from class type C that has a first parameter
6365 // of type "reference to P" (including such a constructor instantiated
6366 // from a template) is excluded from the set of candidate functions when
6367 // constructing an object of type cv D if the argument list has exactly
6368 // one argument and D is reference-related to P and P is reference-related
6369 // to C.
6370 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
6371 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
6372 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
6373 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
6374 QualType C = Context.getRecordType(Constructor->getParent());
6375 QualType D = Context.getRecordType(Shadow->getParent());
6376 SourceLocation Loc = Args.front()->getExprLoc();
6377 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
6378 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
6379 Candidate.Viable = false;
6380 Candidate.FailureKind = ovl_fail_inhctor_slice;
6381 return;
6382 }
6383 }
6384
6385 // Check that the constructor is capable of constructing an object in the
6386 // destination address space.
6387 if (!Qualifiers::isAddressSpaceSupersetOf(
6388 Constructor->getMethodQualifiers().getAddressSpace(),
6389 CandidateSet.getDestAS())) {
6390 Candidate.Viable = false;
6391 Candidate.FailureKind = ovl_fail_object_addrspace_mismatch;
6392 }
6393 }
6394
6395 unsigned NumParams = Proto->getNumParams();
6396
6397 // (C++ 13.3.2p2): A candidate function having fewer than m
6398 // parameters is viable only if it has an ellipsis in its parameter
6399 // list (8.3.5).
6400 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6401 !Proto->isVariadic()) {
6402 Candidate.Viable = false;
6403 Candidate.FailureKind = ovl_fail_too_many_arguments;
6404 return;
6405 }
6406
6407 // (C++ 13.3.2p2): A candidate function having more than m parameters
6408 // is viable only if the (m+1)st parameter has a default argument
6409 // (8.3.6). For the purposes of overload resolution, the
6410 // parameter list is truncated on the right, so that there are
6411 // exactly m parameters.
6412 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
6413 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6414 // Not enough arguments.
6415 Candidate.Viable = false;
6416 Candidate.FailureKind = ovl_fail_too_few_arguments;
6417 return;
6418 }
6419
6420 // (CUDA B.1): Check for invalid calls between targets.
6421 if (getLangOpts().CUDA)
6422 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6423 // Skip the check for callers that are implicit members, because in this
6424 // case we may not yet know what the member's target is; the target is
6425 // inferred for the member automatically, based on the bases and fields of
6426 // the class.
6427 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
6428 Candidate.Viable = false;
6429 Candidate.FailureKind = ovl_fail_bad_target;
6430 return;
6431 }
6432
6433 if (Function->getTrailingRequiresClause()) {
6434 ConstraintSatisfaction Satisfaction;
6435 if (CheckFunctionConstraints(Function, Satisfaction) ||
6436 !Satisfaction.IsSatisfied) {
6437 Candidate.Viable = false;
6438 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
6439 return;
6440 }
6441 }
6442
6443 // Determine the implicit conversion sequences for each of the
6444 // arguments.
6445 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6446 unsigned ConvIdx =
6447 PO == OverloadCandidateParamOrder::Reversed ? 1 - ArgIdx : ArgIdx;
6448 if (Candidate.Conversions[ConvIdx].isInitialized()) {
6449 // We already formed a conversion sequence for this parameter during
6450 // template argument deduction.
6451 } else if (ArgIdx < NumParams) {
6452 // (C++ 13.3.2p3): for F to be a viable function, there shall
6453 // exist for each argument an implicit conversion sequence
6454 // (13.3.3.1) that converts that argument to the corresponding
6455 // parameter of F.
6456 QualType ParamType = Proto->getParamType(ArgIdx);
6457 Candidate.Conversions[ConvIdx] = TryCopyInitialization(
6458 *this, Args[ArgIdx], ParamType, SuppressUserConversions,
6459 /*InOverloadResolution=*/true,
6460 /*AllowObjCWritebackConversion=*/
6461 getLangOpts().ObjCAutoRefCount, AllowExplicitConversions);
6462 if (Candidate.Conversions[ConvIdx].isBad()) {
6463 Candidate.Viable = false;
6464 Candidate.FailureKind = ovl_fail_bad_conversion;
6465 return;
6466 }
6467 } else {
6468 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6469 // argument for which there is no corresponding parameter is
6470 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6471 Candidate.Conversions[ConvIdx].setEllipsis();
6472 }
6473 }
6474
6475 if (EnableIfAttr *FailedAttr =
6476 CheckEnableIf(Function, CandidateSet.getLocation(), Args)) {
6477 Candidate.Viable = false;
6478 Candidate.FailureKind = ovl_fail_enable_if;
6479 Candidate.DeductionFailure.Data = FailedAttr;
6480 return;
6481 }
6482
6483 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6484 Candidate.Viable = false;
6485 Candidate.FailureKind = ovl_fail_ext_disabled;
6486 return;
6487 }
6488}
6489
6490ObjCMethodDecl *
6491Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6492 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6493 if (Methods.size() <= 1)
6494 return nullptr;
6495
6496 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6497 bool Match = true;
6498 ObjCMethodDecl *Method = Methods[b];
6499 unsigned NumNamedArgs = Sel.getNumArgs();
6500 // Method might have more arguments than selector indicates. This is due
6501 // to addition of c-style arguments in method.
6502 if (Method->param_size() > NumNamedArgs)
6503 NumNamedArgs = Method->param_size();
6504 if (Args.size() < NumNamedArgs)
6505 continue;
6506
6507 for (unsigned i = 0; i < NumNamedArgs; i++) {
6508 // We can't do any type-checking on a type-dependent argument.
6509 if (Args[i]->isTypeDependent()) {
6510 Match = false;
6511 break;
6512 }
6513
6514 ParmVarDecl *param = Method->parameters()[i];
6515 Expr *argExpr = Args[i];
6516 assert(argExpr && "SelectBestMethod(): missing expression");
6517
6518 // Strip the unbridged-cast placeholder expression off unless it's
6519 // a consumed argument.
6520 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6521 !param->hasAttr<CFConsumedAttr>())
6522 argExpr = stripARCUnbridgedCast(argExpr);
6523
6524 // If the parameter is __unknown_anytype, move on to the next method.
6525 if (param->getType() == Context.UnknownAnyTy) {
6526 Match = false;
6527 break;
6528 }
6529
6530 ImplicitConversionSequence ConversionState
6531 = TryCopyInitialization(*this, argExpr, param->getType(),
6532 /*SuppressUserConversions*/false,
6533 /*InOverloadResolution=*/true,
6534 /*AllowObjCWritebackConversion=*/
6535 getLangOpts().ObjCAutoRefCount,
6536 /*AllowExplicit*/false);
6537 // This function looks for a reasonably-exact match, so we consider
6538 // incompatible pointer conversions to be a failure here.
6539 if (ConversionState.isBad() ||
6540 (ConversionState.isStandard() &&
6541 ConversionState.Standard.Second ==
6542 ICK_Incompatible_Pointer_Conversion)) {
6543 Match = false;
6544 break;
6545 }
6546 }
6547 // Promote additional arguments to variadic methods.
6548 if (Match && Method->isVariadic()) {
6549 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6550 if (Args[i]->isTypeDependent()) {
6551 Match = false;
6552 break;
6553 }
6554 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6555 nullptr);
6556 if (Arg.isInvalid()) {
6557 Match = false;
6558 break;
6559 }
6560 }
6561 } else {
6562 // Check for extra arguments to non-variadic methods.
6563 if (Args.size() != NumNamedArgs)
6564 Match = false;
6565 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6566 // Special case when selectors have no argument. In this case, select
6567 // one with the most general result type of 'id'.
6568 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6569 QualType ReturnT = Methods[b]->getReturnType();
6570 if (ReturnT->isObjCIdType())
6571 return Methods[b];
6572 }
6573 }
6574 }
6575
6576 if (Match)
6577 return Method;
6578 }
6579 return nullptr;
6580}
6581
6582static bool convertArgsForAvailabilityChecks(
6583 Sema &S, FunctionDecl *Function, Expr *ThisArg, SourceLocation CallLoc,
6584 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap, bool MissingImplicitThis,
6585 Expr *&ConvertedThis, SmallVectorImpl<Expr *> &ConvertedArgs) {
6586 if (ThisArg) {
6587 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6588 assert(!isa<CXXConstructorDecl>(Method) &&
6589 "Shouldn't have `this` for ctors!");
6590 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!");
6591 ExprResult R = S.PerformObjectArgumentInitialization(
6592 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6593 if (R.isInvalid())
6594 return false;
6595 ConvertedThis = R.get();
6596 } else {
6597 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6598 (void)MD;
6599 assert((MissingImplicitThis || MD->isStatic() ||
6600 isa<CXXConstructorDecl>(MD)) &&
6601 "Expected `this` for non-ctor instance methods");
6602 }
6603 ConvertedThis = nullptr;
6604 }
6605
6606 // Ignore any variadic arguments. Converting them is pointless, since the
6607 // user can't refer to them in the function condition.
6608 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6609
6610 // Convert the arguments.
6611 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6612 ExprResult R;
6613 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6614 S.Context, Function->getParamDecl(I)),
6615 SourceLocation(), Args[I]);
6616
6617 if (R.isInvalid())
6618 return false;
6619
6620 ConvertedArgs.push_back(R.get());
6621 }
6622
6623 if (Trap.hasErrorOccurred())
6624 return false;
6625
6626 // Push default arguments if needed.
6627 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6628 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6629 ParmVarDecl *P = Function->getParamDecl(i);
6630 if (!P->hasDefaultArg())
6631 return false;
6632 ExprResult R = S.BuildCXXDefaultArgExpr(CallLoc, Function, P);
6633 if (R.isInvalid())
6634 return false;
6635 ConvertedArgs.push_back(R.get());
6636 }
6637
6638 if (Trap.hasErrorOccurred())
6639 return false;
6640 }
6641 return true;
6642}
6643
6644EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function,
6645 SourceLocation CallLoc,
6646 ArrayRef<Expr *> Args,
6647 bool MissingImplicitThis) {
6648 auto EnableIfAttrs = Function->specific_attrs<EnableIfAttr>();
6649 if (EnableIfAttrs.begin() == EnableIfAttrs.end())
6650 return nullptr;
6651
6652 SFINAETrap Trap(*this);
6653 SmallVector<Expr *, 16> ConvertedArgs;
6654 // FIXME: We should look into making enable_if late-parsed.
6655 Expr *DiscardedThis;
6656 if (!convertArgsForAvailabilityChecks(
6657 *this, Function, /*ThisArg=*/nullptr, CallLoc, Args, Trap,
6658 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6659 return *EnableIfAttrs.begin();
6660
6661 for (auto *EIA : EnableIfAttrs) {
6662 APValue Result;
6663 // FIXME: This doesn't consider value-dependent cases, because doing so is
6664 // very difficult. Ideally, we should handle them more gracefully.
6665 if (EIA->getCond()->isValueDependent() ||
6666 !EIA->getCond()->EvaluateWithSubstitution(
6667 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6668 return EIA;
6669
6670 if (!Result.isInt() || !Result.getInt().getBoolValue())
6671 return EIA;
6672 }
6673 return nullptr;
6674}
6675
6676template <typename CheckFn>
6677static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const NamedDecl *ND,
6678 bool ArgDependent, SourceLocation Loc,
6679 CheckFn &&IsSuccessful) {
6680 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6681 for (const auto *DIA : ND->specific_attrs<DiagnoseIfAttr>()) {
6682 if (ArgDependent == DIA->getArgDependent())
6683 Attrs.push_back(DIA);
6684 }
6685
6686 // Common case: No diagnose_if attributes, so we can quit early.
6687 if (Attrs.empty())
6688 return false;
6689
6690 auto WarningBegin = std::stable_partition(
6691 Attrs.begin(), Attrs.end(),
6692 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6693
6694 // Note that diagnose_if attributes are late-parsed, so they appear in the
6695 // correct order (unlike enable_if attributes).
6696 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6697 IsSuccessful);
6698 if (ErrAttr != WarningBegin) {
6699 const DiagnoseIfAttr *DIA = *ErrAttr;
6700 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6701 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6702 << DIA->getParent() << DIA->getCond()->getSourceRange();
6703 return true;
6704 }
6705
6706 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6707 if (IsSuccessful(DIA)) {
6708 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6709 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6710 << DIA->getParent() << DIA->getCond()->getSourceRange();
6711 }
6712
6713 return false;
6714}
6715
6716bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6717 const Expr *ThisArg,
6718 ArrayRef<const Expr *> Args,
6719 SourceLocation Loc) {
6720 return diagnoseDiagnoseIfAttrsWith(
6721 *this, Function, /*ArgDependent=*/true, Loc,
6722 [&](const DiagnoseIfAttr *DIA) {
6723 APValue Result;
6724 // It's sane to use the same Args for any redecl of this function, since
6725 // EvaluateWithSubstitution only cares about the position of each
6726 // argument in the arg list, not the ParmVarDecl* it maps to.
6727 if (!DIA->getCond()->EvaluateWithSubstitution(
6728 Result, Context, cast<FunctionDecl>(DIA->getParent()), Args, ThisArg))
6729 return false;
6730 return Result.isInt() && Result.getInt().getBoolValue();
6731 });
6732}
6733
6734bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
6735 SourceLocation Loc) {
6736 return diagnoseDiagnoseIfAttrsWith(
6737 *this, ND, /*ArgDependent=*/false, Loc,
6738 [&](const DiagnoseIfAttr *DIA) {
6739 bool Result;
6740 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6741 Result;
6742 });
6743}
6744
6745/// Add all of the function declarations in the given function set to
6746/// the overload candidate set.
6747void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6748 ArrayRef<Expr *> Args,
6749 OverloadCandidateSet &CandidateSet,
6750 TemplateArgumentListInfo *ExplicitTemplateArgs,
6751 bool SuppressUserConversions,
6752 bool PartialOverloading,
6753 bool FirstArgumentIsBase) {
6754 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6755 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6756 ArrayRef<Expr *> FunctionArgs = Args;
6757
6758 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
6759 FunctionDecl *FD =
6760 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
6761
6762 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6763 QualType ObjectType;
6764 Expr::Classification ObjectClassification;
6765 if (Args.size() > 0) {
6766 if (Expr *E = Args[0]) {
6767 // Use the explicit base to restrict the lookup:
6768 ObjectType = E->getType();
6769 // Pointers in the object arguments are implicitly dereferenced, so we
6770 // always classify them as l-values.
6771 if (!ObjectType.isNull() && ObjectType->isPointerType())
6772 ObjectClassification = Expr::Classification::makeSimpleLValue();
6773 else
6774 ObjectClassification = E->Classify(Context);
6775 } // .. else there is an implicit base.
6776 FunctionArgs = Args.slice(1);
6777 }
6778 if (FunTmpl) {
6779 AddMethodTemplateCandidate(
6780 FunTmpl, F.getPair(),
6781 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6782 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6783 FunctionArgs, CandidateSet, SuppressUserConversions,
6784 PartialOverloading);
6785 } else {
6786 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6787 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6788 ObjectClassification, FunctionArgs, CandidateSet,
6789 SuppressUserConversions, PartialOverloading);
6790 }
6791 } else {
6792 // This branch handles both standalone functions and static methods.
6793
6794 // Slice the first argument (which is the base) when we access
6795 // static method as non-static.
6796 if (Args.size() > 0 &&
6797 (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
6798 !isa<CXXConstructorDecl>(FD)))) {
6799 assert(cast<CXXMethodDecl>(FD)->isStatic());
6800 FunctionArgs = Args.slice(1);
6801 }
6802 if (FunTmpl) {
6803 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6804 ExplicitTemplateArgs, FunctionArgs,
6805 CandidateSet, SuppressUserConversions,
6806 PartialOverloading);
6807 } else {
6808 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
6809 SuppressUserConversions, PartialOverloading);
6810 }
6811 }
6812 }
6813}
6814
6815/// AddMethodCandidate - Adds a named decl (which is some kind of
6816/// method) as a method candidate to the given overload set.
6817void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, QualType ObjectType,
6818 Expr::Classification ObjectClassification,
6819 ArrayRef<Expr *> Args,
6820 OverloadCandidateSet &CandidateSet,
6821 bool SuppressUserConversions,
6822 OverloadCandidateParamOrder PO) {
6823 NamedDecl *Decl = FoundDecl.getDecl();
6824 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6825
6826 if (isa<UsingShadowDecl>(Decl))
6827 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6828
6829 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6830 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6831 "Expected a member function template");
6832 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6833 /*ExplicitArgs*/ nullptr, ObjectType,
6834 ObjectClassification, Args, CandidateSet,
6835 SuppressUserConversions, false, PO);
6836 } else {
6837 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6838 ObjectType, ObjectClassification, Args, CandidateSet,
6839 SuppressUserConversions, false, None, PO);
6840 }
6841}
6842
6843/// AddMethodCandidate - Adds the given C++ member function to the set
6844/// of candidate functions, using the given function call arguments
6845/// and the object argument (@c Object). For example, in a call
6846/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6847/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6848/// allow user-defined conversions via constructors or conversion
6849/// operators.
6850void
6851Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6852 CXXRecordDecl *ActingContext, QualType ObjectType,
6853 Expr::Classification ObjectClassification,
6854 ArrayRef<Expr *> Args,
6855 OverloadCandidateSet &CandidateSet,
6856 bool SuppressUserConversions,
6857 bool PartialOverloading,
6858 ConversionSequenceList EarlyConversions,
6859 OverloadCandidateParamOrder PO) {
6860 const FunctionProtoType *Proto
6861 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6862 assert(Proto && "Methods without a prototype cannot be overloaded");
6863 assert(!isa<CXXConstructorDecl>(Method) &&
6864 "Use AddOverloadCandidate for constructors");
6865
6866 if (!CandidateSet.isNewCandidate(Method, PO))
6867 return;
6868
6869 // C++11 [class.copy]p23: [DR1402]
6870 // A defaulted move assignment operator that is defined as deleted is
6871 // ignored by overload resolution.
6872 if (Method->isDefaulted() && Method->isDeleted() &&
6873 Method->isMoveAssignmentOperator())
6874 return;
6875
6876 // Overload resolution is always an unevaluated context.
6877 EnterExpressionEvaluationContext Unevaluated(
6878 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6879
6880 // Add this candidate
6881 OverloadCandidate &Candidate =
6882 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6883 Candidate.FoundDecl = FoundDecl;
6884 Candidate.Function = Method;
6885 Candidate.RewriteKind =
6886 CandidateSet.getRewriteInfo().getRewriteKind(Method, PO);
6887 Candidate.IsSurrogate = false;
6888 Candidate.IgnoreObjectArgument = false;
6889 Candidate.ExplicitCallArguments = Args.size();
6890
6891 unsigned NumParams = Proto->getNumParams();
6892
6893 // (C++ 13.3.2p2): A candidate function having fewer than m
6894 // parameters is viable only if it has an ellipsis in its parameter
6895 // list (8.3.5).
6896 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6897 !Proto->isVariadic()) {
6898 Candidate.Viable = false;
6899 Candidate.FailureKind = ovl_fail_too_many_arguments;
6900 return;
6901 }
6902
6903 // (C++ 13.3.2p2): A candidate function having more than m parameters
6904 // is viable only if the (m+1)st parameter has a default argument
6905 // (8.3.6). For the purposes of overload resolution, the
6906 // parameter list is truncated on the right, so that there are
6907 // exactly m parameters.
6908 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6909 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6910 // Not enough arguments.
6911 Candidate.Viable = false;
6912 Candidate.FailureKind = ovl_fail_too_few_arguments;
6913 return;
6914 }
6915
6916 Candidate.Viable = true;
6917
6918 if (Method->isStatic() || ObjectType.isNull())
6919 // The implicit object argument is ignored.
6920 Candidate.IgnoreObjectArgument = true;
6921 else {
6922 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed ? 1 : 0;
6923 // Determine the implicit conversion sequence for the object
6924 // parameter.
6925 Candidate.Conversions[ConvIdx] = TryObjectArgumentInitialization(
6926 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6927 Method, ActingContext);
6928 if (Candidate.Conversions[ConvIdx].isBad()) {
6929 Candidate.Viable = false;
6930 Candidate.FailureKind = ovl_fail_bad_conversion;
6931 return;
6932 }
6933 }
6934
6935 // (CUDA B.1): Check for invalid calls between targets.
6936 if (getLangOpts().CUDA)
6937 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6938 if (!IsAllowedCUDACall(Caller, Method)) {
6939 Candidate.Viable = false;
6940 Candidate.FailureKind = ovl_fail_bad_target;
6941 return;
6942 }
6943
6944 if (Method->getTrailingRequiresClause()) {
6945 ConstraintSatisfaction Satisfaction;
6946 if (CheckFunctionConstraints(Method, Satisfaction) ||
6947 !Satisfaction.IsSatisfied) {
6948 Candidate.Viable = false;
6949 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
6950 return;
6951 }
6952 }
6953
6954 // Determine the implicit conversion sequences for each of the
6955 // arguments.
6956 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6957 unsigned ConvIdx =
6958 PO == OverloadCandidateParamOrder::Reversed ? 0 : (ArgIdx + 1);
6959 if (Candidate.Conversions[ConvIdx].isInitialized()) {
6960 // We already formed a conversion sequence for this parameter during
6961 // template argument deduction.
6962 } else if (ArgIdx < NumParams) {
6963 // (C++ 13.3.2p3): for F to be a viable function, there shall
6964 // exist for each argument an implicit conversion sequence
6965 // (13.3.3.1) that converts that argument to the corresponding
6966 // parameter of F.
6967 QualType ParamType = Proto->getParamType(ArgIdx);
6968 Candidate.Conversions[ConvIdx]
6969 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6970 SuppressUserConversions,
6971 /*InOverloadResolution=*/true,
6972 /*AllowObjCWritebackConversion=*/
6973 getLangOpts().ObjCAutoRefCount);
6974 if (Candidate.Conversions[ConvIdx].isBad()) {
6975 Candidate.Viable = false;
6976 Candidate.FailureKind = ovl_fail_bad_conversion;
6977 return;
6978 }
6979 } else {
6980 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6981 // argument for which there is no corresponding parameter is
6982 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6983 Candidate.Conversions[ConvIdx].setEllipsis();
6984 }
6985 }
6986
6987 if (EnableIfAttr *FailedAttr =
6988 CheckEnableIf(Method, CandidateSet.getLocation(), Args, true)) {
6989 Candidate.Viable = false;
6990 Candidate.FailureKind = ovl_fail_enable_if;
6991 Candidate.DeductionFailure.Data = FailedAttr;
6992 return;
6993 }
6994
6995 if (Method->isMultiVersion() && Method->hasAttr<TargetAttr>() &&
6996 !Method->getAttr<TargetAttr>()->isDefaultVersion()) {
6997 Candidate.Viable = false;
6998 Candidate.FailureKind = ovl_non_default_multiversion_function;
6999 }
7000}
7001
7002/// Add a C++ member function template as a candidate to the candidate
7003/// set, using template argument deduction to produce an appropriate member
7004/// function template specialization.
7005void Sema::AddMethodTemplateCandidate(
7006 FunctionTemplateDecl *MethodTmpl, DeclAccessPair FoundDecl,
7007 CXXRecordDecl *ActingContext,
7008 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ObjectType,
7009 Expr::Classification ObjectClassification, ArrayRef<Expr *> Args,
7010 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
7011 bool PartialOverloading, OverloadCandidateParamOrder PO) {
7012 if (!CandidateSet.isNewCandidate(MethodTmpl, PO))
7013 return;
7014
7015 // C++ [over.match.funcs]p7:
7016 // In each case where a candidate is a function template, candidate
7017 // function template specializations are generated using template argument
7018 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
7019 // candidate functions in the usual way.113) A given name can refer to one
7020 // or more function templates and also to a set of overloaded non-template
7021 // functions. In such a case, the candidate functions generated from each
7022 // function template are combined with the set of non-template candidate
7023 // functions.
7024 TemplateDeductionInfo Info(CandidateSet.getLocation());
7025 FunctionDecl *Specialization = nullptr;
7026 ConversionSequenceList Conversions;
7027 if (TemplateDeductionResult Result = DeduceTemplateArguments(
7028 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
7029 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
7030 return CheckNonDependentConversions(
7031 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
7032 SuppressUserConversions, ActingContext, ObjectType,
7033 ObjectClassification, PO);
7034 })) {
7035 OverloadCandidate &Candidate =
7036 CandidateSet.addCandidate(Conversions.size(), Conversions);
7037 Candidate.FoundDecl = FoundDecl;
7038 Candidate.Function = MethodTmpl->getTemplatedDecl();
7039 Candidate.Viable = false;
7040 Candidate.RewriteKind =
7041 CandidateSet.getRewriteInfo().getRewriteKind(Candidate.Function, PO);
7042 Candidate.IsSurrogate = false;
7043 Candidate.IgnoreObjectArgument =
7044 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
7045 ObjectType.isNull();
7046 Candidate.ExplicitCallArguments = Args.size();
7047 if (Result == TDK_NonDependentConversionFailure)
7048 Candidate.FailureKind = ovl_fail_bad_conversion;
7049 else {
7050 Candidate.FailureKind = ovl_fail_bad_deduction;
7051 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7052 Info);
7053 }
7054 return;
7055 }
7056
7057 // Add the function template specialization produced by template argument
7058 // deduction as a candidate.
7059 assert(Specialization && "Missing member function template specialization?");
7060 assert(isa<CXXMethodDecl>(Specialization) &&
7061 "Specialization is not a member function?");
7062 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
7063 ActingContext, ObjectType, ObjectClassification, Args,
7064 CandidateSet, SuppressUserConversions, PartialOverloading,
7065 Conversions, PO);
7066}
7067
7068/// Determine whether a given function template has a simple explicit specifier
7069/// or a non-value-dependent explicit-specification that evaluates to true.
7070static bool isNonDependentlyExplicit(FunctionTemplateDecl *FTD) {
7071 return ExplicitSpecifier::getFromDecl(FTD->getTemplatedDecl()).isExplicit();
7072}
7073
7074/// Add a C++ function template specialization as a candidate
7075/// in the candidate set, using template argument deduction to produce
7076/// an appropriate function template specialization.
7077void Sema::AddTemplateOverloadCandidate(
7078 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
7079 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
7080 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
7081 bool PartialOverloading, bool AllowExplicit, ADLCallKind IsADLCandidate,
7082 OverloadCandidateParamOrder PO) {
7083 if (!CandidateSet.isNewCandidate(FunctionTemplate, PO))
7084 return;
7085
7086 // If the function template has a non-dependent explicit specification,
7087 // exclude it now if appropriate; we are not permitted to perform deduction
7088 // and substitution in this case.
7089 if (!AllowExplicit && isNonDependentlyExplicit(FunctionTemplate)) {
7090 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7091 Candidate.FoundDecl = FoundDecl;
7092 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7093 Candidate.Viable = false;
7094 Candidate.FailureKind = ovl_fail_explicit;
7095 return;
7096 }
7097
7098 // C++ [over.match.funcs]p7:
7099 // In each case where a candidate is a function template, candidate
7100 // function template specializations are generated using template argument
7101 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
7102 // candidate functions in the usual way.113) A given name can refer to one
7103 // or more function templates and also to a set of overloaded non-template
7104 // functions. In such a case, the candidate functions generated from each
7105 // function template are combined with the set of non-template candidate
7106 // functions.
7107 TemplateDeductionInfo Info(CandidateSet.getLocation());
7108 FunctionDecl *Specialization = nullptr;
7109 ConversionSequenceList Conversions;
7110 if (TemplateDeductionResult Result = DeduceTemplateArguments(
7111 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
7112 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
7113 return CheckNonDependentConversions(
7114 FunctionTemplate, ParamTypes, Args, CandidateSet, Conversions,
7115 SuppressUserConversions, nullptr, QualType(), {}, PO);
7116 })) {
7117 OverloadCandidate &Candidate =
7118 CandidateSet.addCandidate(Conversions.size(), Conversions);
7119 Candidate.FoundDecl = FoundDecl;
7120 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7121 Candidate.Viable = false;
7122 Candidate.RewriteKind =
7123 CandidateSet.getRewriteInfo().getRewriteKind(Candidate.Function, PO);
7124 Candidate.IsSurrogate = false;
7125 Candidate.IsADLCandidate = IsADLCandidate;
7126 // Ignore the object argument if there is one, since we don't have an object
7127 // type.
7128 Candidate.IgnoreObjectArgument =
7129 isa<CXXMethodDecl>(Candidate.Function) &&
7130 !isa<CXXConstructorDecl>(Candidate.Function);
7131 Candidate.ExplicitCallArguments = Args.size();
7132 if (Result == TDK_NonDependentConversionFailure)
7133 Candidate.FailureKind = ovl_fail_bad_conversion;
7134 else {
7135 Candidate.FailureKind = ovl_fail_bad_deduction;
7136 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7137 Info);
7138 }
7139 return;
7140 }
7141
7142 // Add the function template specialization produced by template argument
7143 // deduction as a candidate.
7144 assert(Specialization && "Missing function template specialization?");
7145 AddOverloadCandidate(
7146 Specialization, FoundDecl, Args, CandidateSet, SuppressUserConversions,
7147 PartialOverloading, AllowExplicit,
7148 /*AllowExplicitConversions*/ false, IsADLCandidate, Conversions, PO);
7149}
7150
7151/// Check that implicit conversion sequences can be formed for each argument
7152/// whose corresponding parameter has a non-dependent type, per DR1391's
7153/// [temp.deduct.call]p10.
7154bool Sema::CheckNonDependentConversions(
7155 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
7156 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
7157 ConversionSequenceList &Conversions, bool SuppressUserConversions,
7158 CXXRecordDecl *ActingContext, QualType ObjectType,
7159 Expr::Classification ObjectClassification, OverloadCandidateParamOrder PO) {
7160 // FIXME: The cases in which we allow explicit conversions for constructor
7161 // arguments never consider calling a constructor template. It's not clear
7162 // that is correct.
7163 const bool AllowExplicit = false;
7164
7165 auto *FD = FunctionTemplate->getTemplatedDecl();
7166 auto *Method = dyn_cast<CXXMethodDecl>(FD);
7167 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
7168 unsigned ThisConversions = HasThisConversion ? 1 : 0;
7169
7170 Conversions =
7171 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
7172
7173 // Overload resolution is always an unevaluated context.
7174 EnterExpressionEvaluationContext Unevaluated(
7175 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7176
7177 // For a method call, check the 'this' conversion here too. DR1391 doesn't
7178 // require that, but this check should never result in a hard error, and
7179 // overload resolution is permitted to sidestep instantiations.
7180 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
7181 !ObjectType.isNull()) {
7182 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed ? 1 : 0;
7183 Conversions[ConvIdx] = TryObjectArgumentInitialization(
7184 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
7185 Method, ActingContext);
7186 if (Conversions[ConvIdx].isBad())
7187 return true;
7188 }
7189
7190 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
7191 ++I) {
7192 QualType ParamType = ParamTypes[I];
7193 if (!ParamType->isDependentType()) {
7194 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed
7195 ? 0
7196 : (ThisConversions + I);
7197 Conversions[ConvIdx]
7198 = TryCopyInitialization(*this, Args[I], ParamType,
7199 SuppressUserConversions,
7200 /*InOverloadResolution=*/true,
7201 /*AllowObjCWritebackConversion=*/
7202 getLangOpts().ObjCAutoRefCount,
7203 AllowExplicit);
7204 if (Conversions[ConvIdx].isBad())
7205 return true;
7206 }
7207 }
7208
7209 return false;
7210}
7211
7212/// Determine whether this is an allowable conversion from the result
7213/// of an explicit conversion operator to the expected type, per C++
7214/// [over.match.conv]p1 and [over.match.ref]p1.
7215///
7216/// \param ConvType The return type of the conversion function.
7217///
7218/// \param ToType The type we are converting to.
7219///
7220/// \param AllowObjCPointerConversion Allow a conversion from one
7221/// Objective-C pointer to another.
7222///
7223/// \returns true if the conversion is allowable, false otherwise.
7224static bool isAllowableExplicitConversion(Sema &S,
7225 QualType ConvType, QualType ToType,
7226 bool AllowObjCPointerConversion) {
7227 QualType ToNonRefType = ToType.getNonReferenceType();
7228
7229 // Easy case: the types are the same.
7230 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
7231 return true;
7232
7233 // Allow qualification conversions.
7234 bool ObjCLifetimeConversion;
7235 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
7236 ObjCLifetimeConversion))
7237 return true;
7238
7239 // If we're not allowed to consider Objective-C pointer conversions,
7240 // we're done.
7241 if (!AllowObjCPointerConversion)
7242 return false;
7243
7244 // Is this an Objective-C pointer conversion?
7245 bool IncompatibleObjC = false;
7246 QualType ConvertedType;
7247 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
7248 IncompatibleObjC);
7249}
7250
7251/// AddConversionCandidate - Add a C++ conversion function as a
7252/// candidate in the candidate set (C++ [over.match.conv],
7253/// C++ [over.match.copy]). From is the expression we're converting from,
7254/// and ToType is the type that we're eventually trying to convert to
7255/// (which may or may not be the same type as the type that the
7256/// conversion function produces).
7257void Sema::AddConversionCandidate(
7258 CXXConversionDecl *Conversion, DeclAccessPair FoundDecl,
7259 CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
7260 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
7261 bool AllowExplicit, bool AllowResultConversion) {
7262 assert(!Conversion->getDescribedFunctionTemplate() &&
7263 "Conversion function templates use AddTemplateConversionCandidate");
7264 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
7265 if (!CandidateSet.isNewCandidate(Conversion))
7266 return;
7267
7268 // If the conversion function has an undeduced return type, trigger its
7269 // deduction now.
7270 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
7271 if (DeduceReturnType(Conversion, From->getExprLoc()))
7272 return;
7273 ConvType = Conversion->getConversionType().getNonReferenceType();
7274 }
7275
7276 // If we don't allow any conversion of the result type, ignore conversion
7277 // functions that don't convert to exactly (possibly cv-qualified) T.
7278 if (!AllowResultConversion &&
7279 !Context.hasSameUnqualifiedType(Conversion->getConversionType(), ToType))
7280 return;
7281
7282 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
7283 // operator is only a candidate if its return type is the target type or
7284 // can be converted to the target type with a qualification conversion.
7285 //
7286 // FIXME: Include such functions in the candidate list and explain why we
7287 // can't select them.
7288 if (Conversion->isExplicit() &&
7289 !isAllowableExplicitConversion(*this, ConvType, ToType,
7290 AllowObjCConversionOnExplicit))
7291 return;
7292
7293 // Overload resolution is always an unevaluated context.
7294 EnterExpressionEvaluationContext Unevaluated(
7295 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7296
7297 // Add this candidate
7298 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
7299 Candidate.FoundDecl = FoundDecl;
7300 Candidate.Function = Conversion;
7301 Candidate.IsSurrogate = false;
7302 Candidate.IgnoreObjectArgument = false;
7303 Candidate.FinalConversion.setAsIdentityConversion();
7304 Candidate.FinalConversion.setFromType(ConvType);
7305 Candidate.FinalConversion.setAllToTypes(ToType);
7306 Candidate.Viable = true;
7307 Candidate.ExplicitCallArguments = 1;
7308
7309 // Explicit functions are not actually candidates at all if we're not
7310 // allowing them in this context, but keep them around so we can point
7311 // to them in diagnostics.
7312 if (!AllowExplicit && Conversion->isExplicit()) {
7313 Candidate.Viable = false;
7314 Candidate.FailureKind = ovl_fail_explicit;
7315 return;
7316 }
7317
7318 // C++ [over.match.funcs]p4:
7319 // For conversion functions, the function is considered to be a member of
7320 // the class of the implicit implied object argument for the purpose of
7321 // defining the type of the implicit object parameter.
7322 //
7323 // Determine the implicit conversion sequence for the implicit
7324 // object parameter.
7325 QualType ImplicitParamType = From->getType();
7326 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
7327 ImplicitParamType = FromPtrType->getPointeeType();
7328 CXXRecordDecl *ConversionContext
7329 = cast<CXXRecordDecl>(ImplicitParamType->castAs<RecordType>()->getDecl());
7330
7331 Candidate.Conversions[0] = TryObjectArgumentInitialization(
7332 *this, CandidateSet.getLocation(), From->getType(),
7333 From->Classify(Context), Conversion, ConversionContext);
7334
7335 if (Candidate.Conversions[0].isBad()) {
7336 Candidate.Viable = false;
7337 Candidate.FailureKind = ovl_fail_bad_conversion;
7338 return;
7339 }
7340
7341 if (Conversion->getTrailingRequiresClause()) {
7342 ConstraintSatisfaction Satisfaction;
7343 if (CheckFunctionConstraints(Conversion, Satisfaction) ||
7344 !Satisfaction.IsSatisfied) {
7345 Candidate.Viable = false;
7346 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
7347 return;
7348 }
7349 }
7350
7351 // We won't go through a user-defined type conversion function to convert a
7352 // derived to base as such conversions are given Conversion Rank. They only
7353 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
7354 QualType FromCanon
7355 = Context.getCanonicalType(From->getType().getUnqualifiedType());
7356 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
7357 if (FromCanon == ToCanon ||
7358 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
7359 Candidate.Viable = false;
7360 Candidate.FailureKind = ovl_fail_trivial_conversion;
7361 return;
7362 }
7363
7364 // To determine what the conversion from the result of calling the
7365 // conversion function to the type we're eventually trying to
7366 // convert to (ToType), we need to synthesize a call to the
7367 // conversion function and attempt copy initialization from it. This
7368 // makes sure that we get the right semantics with respect to
7369 // lvalues/rvalues and the type. Fortunately, we can allocate this
7370 // call on the stack and we don't need its arguments to be
7371 // well-formed.
7372 DeclRefExpr ConversionRef(Context, Conversion, false, Conversion->getType(),
7373 VK_LValue, From->getBeginLoc());
7374 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
7375 Context.getPointerType(Conversion->getType()),
7376 CK_FunctionToPointerDecay, &ConversionRef,
7377 VK_RValue, FPOptionsOverride());
7378
7379 QualType ConversionType = Conversion->getConversionType();
7380 if (!isCompleteType(From->getBeginLoc(), ConversionType)) {
7381 Candidate.Viable = false;
7382 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7383 return;
7384 }
7385
7386 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
7387
7388 // Note that it is safe to allocate CallExpr on the stack here because
7389 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
7390 // allocator).
7391 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
7392
7393 alignas(CallExpr) char Buffer[sizeof(CallExpr) + sizeof(Stmt *)];
7394 CallExpr *TheTemporaryCall = CallExpr::CreateTemporary(
7395 Buffer, &ConversionFn, CallResultType, VK, From->getBeginLoc());
7396
7397 ImplicitConversionSequence ICS =
7398 TryCopyInitialization(*this, TheTemporaryCall, ToType,
7399 /*SuppressUserConversions=*/true,
7400 /*InOverloadResolution=*/false,
7401 /*AllowObjCWritebackConversion=*/false);
7402
7403 switch (ICS.getKind()) {
7404 case ImplicitConversionSequence::StandardConversion:
7405 Candidate.FinalConversion = ICS.Standard;
7406
7407 // C++ [over.ics.user]p3:
7408 // If the user-defined conversion is specified by a specialization of a
7409 // conversion function template, the second standard conversion sequence
7410 // shall have exact match rank.
7411 if (Conversion->getPrimaryTemplate() &&
7412 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
7413 Candidate.Viable = false;
7414 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
7415 return;
7416 }
7417
7418 // C++0x [dcl.init.ref]p5:
7419 // In the second case, if the reference is an rvalue reference and
7420 // the second standard conversion sequence of the user-defined
7421 // conversion sequence includes an lvalue-to-rvalue conversion, the
7422 // program is ill-formed.
7423 if (ToType->isRValueReferenceType() &&
7424 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
7425 Candidate.Viable = false;
7426 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7427 return;
7428 }
7429 break;
7430
7431 case ImplicitConversionSequence::BadConversion:
7432 Candidate.Viable = false;
7433 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7434 return;
7435
7436 default:
7437 llvm_unreachable(
7438 "Can only end up with a standard conversion sequence or failure");
7439 }
7440
7441 if (EnableIfAttr *FailedAttr =
7442 CheckEnableIf(Conversion, CandidateSet.getLocation(), None)) {
7443 Candidate.Viable = false;
7444 Candidate.FailureKind = ovl_fail_enable_if;
7445 Candidate.DeductionFailure.Data = FailedAttr;
7446 return;
7447 }
7448
7449 if (Conversion->isMultiVersion() && Conversion->hasAttr<TargetAttr>() &&
7450 !Conversion->getAttr<TargetAttr>()->isDefaultVersion()) {
7451 Candidate.Viable = false;
7452 Candidate.FailureKind = ovl_non_default_multiversion_function;
7453 }
7454}
7455
7456/// Adds a conversion function template specialization
7457/// candidate to the overload set, using template argument deduction
7458/// to deduce the template arguments of the conversion function
7459/// template from the type that we are converting to (C++
7460/// [temp.deduct.conv]).
7461void Sema::AddTemplateConversionCandidate(
7462 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
7463 CXXRecordDecl *ActingDC, Expr *From, QualType ToType,
7464 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
7465 bool AllowExplicit, bool AllowResultConversion) {
7466 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
7467 "Only conversion function templates permitted here");
7468
7469 if (!CandidateSet.isNewCandidate(FunctionTemplate))
7470 return;
7471
7472 // If the function template has a non-dependent explicit specification,
7473 // exclude it now if appropriate; we are not permitted to perform deduction
7474 // and substitution in this case.
7475 if (!AllowExplicit && isNonDependentlyExplicit(FunctionTemplate)) {
7476 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7477 Candidate.FoundDecl = FoundDecl;
7478 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7479 Candidate.Viable = false;
7480 Candidate.FailureKind = ovl_fail_explicit;
7481 return;
7482 }
7483
7484 TemplateDeductionInfo Info(CandidateSet.getLocation());
7485 CXXConversionDecl *Specialization = nullptr;
7486 if (TemplateDeductionResult Result
7487 = DeduceTemplateArguments(FunctionTemplate, ToType,
7488 Specialization, Info)) {
7489 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7490 Candidate.FoundDecl = FoundDecl;
7491 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7492 Candidate.Viable = false;
7493 Candidate.FailureKind = ovl_fail_bad_deduction;
7494 Candidate.IsSurrogate = false;
7495 Candidate.IgnoreObjectArgument = false;
7496 Candidate.ExplicitCallArguments = 1;
7497 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7498 Info);
7499 return;
7500 }
7501
7502 // Add the conversion function template specialization produced by
7503 // template argument deduction as a candidate.
7504 assert(Specialization && "Missing function template specialization?");
7505 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
7506 CandidateSet, AllowObjCConversionOnExplicit,
7507 AllowExplicit, AllowResultConversion);
7508}
7509
7510/// AddSurrogateCandidate - Adds a "surrogate" candidate function that
7511/// converts the given @c Object to a function pointer via the
7512/// conversion function @c Conversion, and then attempts to call it
7513/// with the given arguments (C++ [over.call.object]p2-4). Proto is
7514/// the type of function that we'll eventually be calling.
7515void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
7516 DeclAccessPair FoundDecl,
7517 CXXRecordDecl *ActingContext,
7518 const FunctionProtoType *Proto,
7519 Expr *Object,
7520 ArrayRef<Expr *> Args,
7521 OverloadCandidateSet& CandidateSet) {
7522 if (!CandidateSet.isNewCandidate(Conversion))
7523 return;
7524
7525 // Overload resolution is always an unevaluated context.
7526 EnterExpressionEvaluationContext Unevaluated(
7527 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7528
7529 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
7530 Candidate.FoundDecl = FoundDecl;
7531 Candidate.Function = nullptr;
7532 Candidate.Surrogate = Conversion;
7533 Candidate.Viable = true;
7534 Candidate.IsSurrogate = true;
7535 Candidate.IgnoreObjectArgument = false;
7536 Candidate.ExplicitCallArguments = Args.size();
7537
7538 // Determine the implicit conversion sequence for the implicit
7539 // object parameter.
7540 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7541 *this, CandidateSet.getLocation(), Object->getType(),
7542 Object->Classify(Context), Conversion, ActingContext);
7543 if (ObjectInit.isBad()) {
7544 Candidate.Viable = false;
7545 Candidate.FailureKind = ovl_fail_bad_conversion;
7546 Candidate.Conversions[0] = ObjectInit;
7547 return;
7548 }
7549
7550 // The first conversion is actually a user-defined conversion whose
7551 // first conversion is ObjectInit's standard conversion (which is
7552 // effectively a reference binding). Record it as such.
7553 Candidate.Conversions[0].setUserDefined();
7554 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7555 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7556 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7557 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7558 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7559 Candidate.Conversions[0].UserDefined.After
7560 = Candidate.Conversions[0].UserDefined.Before;
7561 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7562
7563 // Find the
7564 unsigned NumParams = Proto->getNumParams();
7565
7566 // (C++ 13.3.2p2): A candidate function having fewer than m
7567 // parameters is viable only if it has an ellipsis in its parameter
7568 // list (8.3.5).
7569 if (Args.size() > NumParams && !Proto->isVariadic()) {
7570 Candidate.Viable = false;
7571 Candidate.FailureKind = ovl_fail_too_many_arguments;
7572 return;
7573 }
7574
7575 // Function types don't have any default arguments, so just check if
7576 // we have enough arguments.
7577 if (Args.size() < NumParams) {
7578 // Not enough arguments.
7579 Candidate.Viable = false;
7580 Candidate.FailureKind = ovl_fail_too_few_arguments;
7581 return;
7582 }
7583
7584 // Determine the implicit conversion sequences for each of the
7585 // arguments.
7586 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7587 if (ArgIdx < NumParams) {
7588 // (C++ 13.3.2p3): for F to be a viable function, there shall
7589 // exist for each argument an implicit conversion sequence
7590 // (13.3.3.1) that converts that argument to the corresponding
7591 // parameter of F.
7592 QualType ParamType = Proto->getParamType(ArgIdx);
7593 Candidate.Conversions[ArgIdx + 1]
7594 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7595 /*SuppressUserConversions=*/false,
7596 /*InOverloadResolution=*/false,
7597 /*AllowObjCWritebackConversion=*/
7598 getLangOpts().ObjCAutoRefCount);
7599 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7600 Candidate.Viable = false;
7601 Candidate.FailureKind = ovl_fail_bad_conversion;
7602 return;
7603 }
7604 } else {
7605 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7606 // argument for which there is no corresponding parameter is
7607 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7608 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7609 }
7610 }
7611
7612 if (EnableIfAttr *FailedAttr =
7613 CheckEnableIf(Conversion, CandidateSet.getLocation(), None)) {
7614 Candidate.Viable = false;
7615 Candidate.FailureKind = ovl_fail_enable_if;
7616 Candidate.DeductionFailure.Data = FailedAttr;
7617 return;
7618 }
7619}
7620
7621/// Add all of the non-member operator function declarations in the given
7622/// function set to the overload candidate set.
7623void Sema::AddNonMemberOperatorCandidates(
7624 const UnresolvedSetImpl &Fns, ArrayRef<Expr *> Args,
7625 OverloadCandidateSet &CandidateSet,
7626 TemplateArgumentListInfo *ExplicitTemplateArgs) {
7627 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
7628 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
7629 ArrayRef<Expr *> FunctionArgs = Args;
7630
7631 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
7632 FunctionDecl *FD =
7633 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
7634
7635 // Don't consider rewritten functions if we're not rewriting.
7636 if (!CandidateSet.getRewriteInfo().isAcceptableCandidate(FD))
7637 continue;
7638
7639 assert(!isa<CXXMethodDecl>(FD) &&
7640 "unqualified operator lookup found a member function");
7641
7642 if (FunTmpl) {
7643 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), ExplicitTemplateArgs,
7644 FunctionArgs, CandidateSet);
7645 if (CandidateSet.getRewriteInfo().shouldAddReversed(Context, FD))
7646 AddTemplateOverloadCandidate(
7647 FunTmpl, F.getPair(), ExplicitTemplateArgs,
7648 {FunctionArgs[1], FunctionArgs[0]}, CandidateSet, false, false,
7649 true, ADLCallKind::NotADL, OverloadCandidateParamOrder::Reversed);
7650 } else {
7651 if (ExplicitTemplateArgs)
7652 continue;
7653 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet);
7654 if (CandidateSet.getRewriteInfo().shouldAddReversed(Context, FD))
7655 AddOverloadCandidate(FD, F.getPair(),
7656 {FunctionArgs[1], FunctionArgs[0]}, CandidateSet,
7657 false, false, true, false, ADLCallKind::NotADL,
7658 None, OverloadCandidateParamOrder::Reversed);
7659 }
7660 }
7661}
7662
7663/// Add overload candidates for overloaded operators that are
7664/// member functions.
7665///
7666/// Add the overloaded operator candidates that are member functions
7667/// for the operator Op that was used in an operator expression such
7668/// as "x Op y". , Args/NumArgs provides the operator arguments, and
7669/// CandidateSet will store the added overload candidates. (C++
7670/// [over.match.oper]).
7671void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7672 SourceLocation OpLoc,
7673 ArrayRef<Expr *> Args,
7674 OverloadCandidateSet &CandidateSet,
7675 OverloadCandidateParamOrder PO) {
7676 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7677
7678 // C++ [over.match.oper]p3:
7679 // For a unary operator @ with an operand of a type whose
7680 // cv-unqualified version is T1, and for a binary operator @ with
7681 // a left operand of a type whose cv-unqualified version is T1 and
7682 // a right operand of a type whose cv-unqualified version is T2,
7683 // three sets of candidate functions, designated member
7684 // candidates, non-member candidates and built-in candidates, are
7685 // constructed as follows:
7686 QualType T1 = Args[0]->getType();
7687
7688 // -- If T1 is a complete class type or a class currently being
7689 // defined, the set of member candidates is the result of the
7690 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7691 // the set of member candidates is empty.
7692 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7693 // Complete the type if it can be completed.
7694 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7695 return;
7696 // If the type is neither complete nor being defined, bail out now.
7697 if (!T1Rec->getDecl()->getDefinition())
7698 return;
7699
7700 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7701 LookupQualifiedName(Operators, T1Rec->getDecl());
7702 Operators.suppressDiagnostics();
7703
7704 for (LookupResult::iterator Oper = Operators.begin(),
7705 OperEnd = Operators.end();
7706 Oper != OperEnd;
7707 ++Oper)
7708 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7709 Args[0]->Classify(Context), Args.slice(1),
7710 CandidateSet, /*SuppressUserConversion=*/false, PO);
7711 }
7712}
7713
7714/// AddBuiltinCandidate - Add a candidate for a built-in
7715/// operator. ResultTy and ParamTys are the result and parameter types
7716/// of the built-in candidate, respectively. Args and NumArgs are the
7717/// arguments being passed to the candidate. IsAssignmentOperator
7718/// should be true when this built-in candidate is an assignment
7719/// operator. NumContextualBoolArguments is the number of arguments
7720/// (at the beginning of the argument list) that will be contextually
7721/// converted to bool.
7722void Sema::AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
7723 OverloadCandidateSet& CandidateSet,
7724 bool IsAssignmentOperator,
7725 unsigned NumContextualBoolArguments) {
7726 // Overload resolution is always an unevaluated context.
7727 EnterExpressionEvaluationContext Unevaluated(
7728 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7729
7730 // Add this candidate
7731 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7732 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7733 Candidate.Function = nullptr;
7734 Candidate.IsSurrogate = false;
7735 Candidate.IgnoreObjectArgument = false;
7736 std::copy(ParamTys, ParamTys + Args.size(), Candidate.BuiltinParamTypes);
7737
7738 // Determine the implicit conversion sequences for each of the
7739 // arguments.
7740 Candidate.Viable = true;
7741 Candidate.ExplicitCallArguments = Args.size();
7742 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7743 // C++ [over.match.oper]p4:
7744 // For the built-in assignment operators, conversions of the
7745 // left operand are restricted as follows:
7746 // -- no temporaries are introduced to hold the left operand, and
7747 // -- no user-defined conversions are applied to the left
7748 // operand to achieve a type match with the left-most
7749 // parameter of a built-in candidate.
7750 //
7751 // We block these conversions by turning off user-defined
7752 // conversions, since that is the only way that initialization of
7753 // a reference to a non-class type can occur from something that
7754 // is not of the same type.
7755 if (ArgIdx < NumContextualBoolArguments) {
7756 assert(ParamTys[ArgIdx] == Context.BoolTy &&
7757 "Contextual conversion to bool requires bool type");
7758 Candidate.Conversions[ArgIdx]
7759 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7760 } else {
7761 Candidate.Conversions[ArgIdx]
7762 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7763 ArgIdx == 0 && IsAssignmentOperator,
7764 /*InOverloadResolution=*/false,
7765 /*AllowObjCWritebackConversion=*/
7766 getLangOpts().ObjCAutoRefCount);
7767 }
7768 if (Candidate.Conversions[ArgIdx].isBad()) {
7769 Candidate.Viable = false;
7770 Candidate.FailureKind = ovl_fail_bad_conversion;
7771 break;
7772 }
7773 }
7774}
7775
7776namespace {
7777
7778/// BuiltinCandidateTypeSet - A set of types that will be used for the
7779/// candidate operator functions for built-in operators (C++
7780/// [over.built]). The types are separated into pointer types and
7781/// enumeration types.
7782class BuiltinCandidateTypeSet {
7783 /// TypeSet - A set of types.
7784 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7785 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7786
7787 /// PointerTypes - The set of pointer types that will be used in the
7788 /// built-in candidates.
7789 TypeSet PointerTypes;
7790
7791 /// MemberPointerTypes - The set of member pointer types that will be
7792 /// used in the built-in candidates.
7793 TypeSet MemberPointerTypes;
7794
7795 /// EnumerationTypes - The set of enumeration types that will be
7796 /// used in the built-in candidates.
7797 TypeSet EnumerationTypes;
7798
7799 /// The set of vector types that will be used in the built-in
7800 /// candidates.
7801 TypeSet VectorTypes;
7802
7803 /// The set of matrix types that will be used in the built-in
7804 /// candidates.
7805 TypeSet MatrixTypes;
7806
7807 /// A flag indicating non-record types are viable candidates
7808 bool HasNonRecordTypes;
7809
7810 /// A flag indicating whether either arithmetic or enumeration types
7811 /// were present in the candidate set.
7812 bool HasArithmeticOrEnumeralTypes;
7813
7814 /// A flag indicating whether the nullptr type was present in the
7815 /// candidate set.
7816 bool HasNullPtrType;
7817
7818 /// Sema - The semantic analysis instance where we are building the
7819 /// candidate type set.
7820 Sema &SemaRef;
7821
7822 /// Context - The AST context in which we will build the type sets.
7823 ASTContext &Context;
7824
7825 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7826 const Qualifiers &VisibleQuals);
7827 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7828
7829public:
7830 /// iterator - Iterates through the types that are part of the set.
7831 typedef TypeSet::iterator iterator;
7832
7833 BuiltinCandidateTypeSet(Sema &SemaRef)
7834 : HasNonRecordTypes(false),
7835 HasArithmeticOrEnumeralTypes(false),
7836 HasNullPtrType(false),
7837 SemaRef(SemaRef),
7838 Context(SemaRef.Context) { }
7839
7840 void AddTypesConvertedFrom(QualType Ty,
7841 SourceLocation Loc,
7842 bool AllowUserConversions,
7843 bool AllowExplicitConversions,
7844 const Qualifiers &VisibleTypeConversionsQuals);
7845
7846 llvm::iterator_range<iterator> pointer_types() { return PointerTypes; }
7847 llvm::iterator_range<iterator> member_pointer_types() {
7848 return MemberPointerTypes;
7849 }
7850 llvm::iterator_range<iterator> enumeration_types() {
7851 return EnumerationTypes;
7852 }
7853 llvm::iterator_range<iterator> vector_types() { return VectorTypes; }
7854 llvm::iterator_range<iterator> matrix_types() { return MatrixTypes; }
7855
7856 bool containsMatrixType(QualType Ty) const { return MatrixTypes.count(Ty); }
7857 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7858 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7859 bool hasNullPtrType() const { return HasNullPtrType; }
7860};
7861
7862} // end anonymous namespace
7863
7864/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7865/// the set of pointer types along with any more-qualified variants of
7866/// that type. For example, if @p Ty is "int const *", this routine
7867/// will add "int const *", "int const volatile *", "int const
7868/// restrict *", and "int const volatile restrict *" to the set of
7869/// pointer types. Returns true if the add of @p Ty itself succeeded,
7870/// false otherwise.
7871///
7872/// FIXME: what to do about extended qualifiers?
7873bool
7874BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7875 const Qualifiers &VisibleQuals) {
7876
7877 // Insert this type.
7878 if (!PointerTypes.insert(Ty))
7879 return false;
7880
7881 QualType PointeeTy;
7882 const PointerType *PointerTy = Ty->getAs<PointerType>();
7883 bool buildObjCPtr = false;
7884 if (!PointerTy) {
7885 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7886 PointeeTy = PTy->getPointeeType();
7887 buildObjCPtr = true;
7888 } else {
7889 PointeeTy = PointerTy->getPointeeType();
7890 }
7891
7892 // Don't add qualified variants of arrays. For one, they're not allowed
7893 // (the qualifier would sink to the element type), and for another, the
7894 // only overload situation where it matters is subscript or pointer +- int,
7895 // and those shouldn't have qualifier variants anyway.
7896 if (PointeeTy->isArrayType())
7897 return true;
7898
7899 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7900 bool hasVolatile = VisibleQuals.hasVolatile();
7901 bool hasRestrict = VisibleQuals.hasRestrict();
7902
7903 // Iterate through all strict supersets of BaseCVR.
7904 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7905 if ((CVR | BaseCVR) != CVR) continue;
7906 // Skip over volatile if no volatile found anywhere in the types.
7907 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7908
7909 // Skip over restrict if no restrict found anywhere in the types, or if
7910 // the type cannot be restrict-qualified.
7911 if ((CVR & Qualifiers::Restrict) &&
7912 (!hasRestrict ||
7913 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7914 continue;
7915
7916 // Build qualified pointee type.
7917 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7918
7919 // Build qualified pointer type.
7920 QualType QPointerTy;
7921 if (!buildObjCPtr)
7922 QPointerTy = Context.getPointerType(QPointeeTy);
7923 else
7924 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7925
7926 // Insert qualified pointer type.
7927 PointerTypes.insert(QPointerTy);
7928 }
7929
7930 return true;
7931}
7932
7933/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7934/// to the set of pointer types along with any more-qualified variants of
7935/// that type. For example, if @p Ty is "int const *", this routine
7936/// will add "int const *", "int const volatile *", "int const
7937/// restrict *", and "int const volatile restrict *" to the set of
7938/// pointer types. Returns true if the add of @p Ty itself succeeded,
7939/// false otherwise.
7940///
7941/// FIXME: what to do about extended qualifiers?
7942bool
7943BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7944 QualType Ty) {
7945 // Insert this type.
7946 if (!MemberPointerTypes.insert(Ty))
7947 return false;
7948
7949 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7950 assert(PointerTy && "type was not a member pointer type!");
7951
7952 QualType PointeeTy = PointerTy->getPointeeType();
7953 // Don't add qualified variants of arrays. For one, they're not allowed
7954 // (the qualifier would sink to the element type), and for another, the
7955 // only overload situation where it matters is subscript or pointer +- int,
7956 // and those shouldn't have qualifier variants anyway.
7957 if (PointeeTy->isArrayType())
7958 return true;
7959 const Type *ClassTy = PointerTy->getClass();
7960
7961 // Iterate through all strict supersets of the pointee type's CVR
7962 // qualifiers.
7963 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7964 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7965 if ((CVR | BaseCVR) != CVR) continue;
7966
7967 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7968 MemberPointerTypes.insert(
7969 Context.getMemberPointerType(QPointeeTy, ClassTy));
7970 }
7971
7972 return true;
7973}
7974
7975/// AddTypesConvertedFrom - Add each of the types to which the type @p
7976/// Ty can be implicit converted to the given set of @p Types. We're
7977/// primarily interested in pointer types and enumeration types. We also
7978/// take member pointer types, for the conditional operator.
7979/// AllowUserConversions is true if we should look at the conversion
7980/// functions of a class type, and AllowExplicitConversions if we
7981/// should also include the explicit conversion functions of a class
7982/// type.
7983void
7984BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7985 SourceLocation Loc,
7986 bool AllowUserConversions,
7987 bool AllowExplicitConversions,
7988 const Qualifiers &VisibleQuals) {
7989 // Only deal with canonical types.
7990 Ty = Context.getCanonicalType(Ty);
7991
7992 // Look through reference types; they aren't part of the type of an
7993 // expression for the purposes of conversions.
7994 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7995 Ty = RefTy->getPointeeType();
7996
7997 // If we're dealing with an array type, decay to the pointer.
7998 if (Ty->isArrayType())
7999 Ty = SemaRef.Context.getArrayDecayedType(Ty);
8000
8001 // Otherwise, we don't care about qualifiers on the type.
8002 Ty = Ty.getLocalUnqualifiedType();
8003
8004 // Flag if we ever add a non-record type.
8005 const RecordType *TyRec = Ty->getAs<RecordType>();
8006 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
8007
8008 // Flag if we encounter an arithmetic type.
8009 HasArithmeticOrEnumeralTypes =
8010 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
8011
8012 if (Ty->isObjCIdType() || Ty->isObjCClassType())
8013 PointerTypes.insert(Ty);
8014 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
8015 // Insert our type, and its more-qualified variants, into the set
8016 // of types.
8017 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
8018 return;
8019 } else if (Ty->isMemberPointerType()) {
8020 // Member pointers are far easier, since the pointee can't be converted.
8021 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
8022 return;
8023 } else if (Ty->isEnumeralType()) {
8024 HasArithmeticOrEnumeralTypes = true;
8025 EnumerationTypes.insert(Ty);
8026 } else if (Ty->isVectorType()) {
8027 // We treat vector types as arithmetic types in many contexts as an
8028 // extension.
8029 HasArithmeticOrEnumeralTypes = true;
8030 VectorTypes.insert(Ty);
8031 } else if (Ty->isMatrixType()) {
8032 // Similar to vector types, we treat vector types as arithmetic types in
8033 // many contexts as an extension.
8034 HasArithmeticOrEnumeralTypes = true;
8035 MatrixTypes.insert(Ty);
8036 } else if (Ty->isNullPtrType()) {
8037 HasNullPtrType = true;
8038 } else if (AllowUserConversions && TyRec) {
8039 // No conversion functions in incomplete types.
8040 if (!SemaRef.isCompleteType(Loc, Ty))
8041 return;
8042
8043 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
8044 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
8045 if (isa<UsingShadowDecl>(D))
8046 D = cast<UsingShadowDecl>(D)->getTargetDecl();
8047
8048 // Skip conversion function templates; they don't tell us anything
8049 // about which builtin types we can convert to.
8050 if (isa<FunctionTemplateDecl>(D))
8051 continue;
8052
8053 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
8054 if (AllowExplicitConversions || !Conv->isExplicit()) {
8055 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
8056 VisibleQuals);
8057 }
8058 }
8059 }
8060}
8061/// Helper function for adjusting address spaces for the pointer or reference
8062/// operands of builtin operators depending on the argument.
8063static QualType AdjustAddressSpaceForBuiltinOperandType(Sema &S, QualType T,
8064 Expr *Arg) {
8065 return S.Context.getAddrSpaceQualType(T, Arg->getType().getAddressSpace());
8066}
8067
8068/// Helper function for AddBuiltinOperatorCandidates() that adds
8069/// the volatile- and non-volatile-qualified assignment operators for the
8070/// given type to the candidate set.
8071static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
8072 QualType T,
8073 ArrayRef<Expr *> Args,
8074 OverloadCandidateSet &CandidateSet) {
8075 QualType ParamTypes[2];
8076
8077 // T& operator=(T&, T)
8078 ParamTypes[0] = S.Context.getLValueReferenceType(
8079 AdjustAddressSpaceForBuiltinOperandType(S, T, Args[0]));
8080 ParamTypes[1] = T;
8081 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8082 /*IsAssignmentOperator=*/true);
8083
8084 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
8085 // volatile T& operator=(volatile T&, T)
8086 ParamTypes[0] = S.Context.getLValueReferenceType(
8087 AdjustAddressSpaceForBuiltinOperandType(S, S.Context.getVolatileType(T),
8088 Args[0]));
8089 ParamTypes[1] = T;
8090 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8091 /*IsAssignmentOperator=*/true);
8092 }
8093}
8094
8095/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
8096/// if any, found in visible type conversion functions found in ArgExpr's type.
8097static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
8098 Qualifiers VRQuals;
8099 const RecordType *TyRec;
8100 if (const MemberPointerType *RHSMPType =
8101 ArgExpr->getType()->getAs<MemberPointerType>())
8102 TyRec = RHSMPType->getClass()->getAs<RecordType>();
8103 else
8104 TyRec = ArgExpr->getType()->getAs<RecordType>();
8105 if (!TyRec) {
8106 // Just to be safe, assume the worst case.
8107 VRQuals.addVolatile();
8108 VRQuals.addRestrict();
8109 return VRQuals;
8110 }
8111
8112 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
8113 if (!ClassDecl->hasDefinition())
8114 return VRQuals;
8115
8116 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
8117 if (isa<UsingShadowDecl>(D))
8118 D = cast<UsingShadowDecl>(D)->getTargetDecl();
8119 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
8120 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
8121 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
8122 CanTy = ResTypeRef->getPointeeType();
8123 // Need to go down the pointer/mempointer chain and add qualifiers
8124 // as see them.
8125 bool done = false;
8126 while (!done) {
8127 if (CanTy.isRestrictQualified())
8128 VRQuals.addRestrict();
8129 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
8130 CanTy = ResTypePtr->getPointeeType();
8131 else if (const MemberPointerType *ResTypeMPtr =
8132 CanTy->getAs<MemberPointerType>())
8133 CanTy = ResTypeMPtr->getPointeeType();
8134 else
8135 done = true;
8136 if (CanTy.isVolatileQualified())
8137 VRQuals.addVolatile();
8138 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
8139 return VRQuals;
8140 }
8141 }
8142 }
8143 return VRQuals;
8144}
8145
8146namespace {
8147
8148/// Helper class to manage the addition of builtin operator overload
8149/// candidates. It provides shared state and utility methods used throughout
8150/// the process, as well as a helper method to add each group of builtin
8151/// operator overloads from the standard to a candidate set.
8152class BuiltinOperatorOverloadBuilder {
8153 // Common instance state available to all overload candidate addition methods.
8154 Sema &S;
8155 ArrayRef<Expr *> Args;
8156 Qualifiers VisibleTypeConversionsQuals;
8157 bool HasArithmeticOrEnumeralCandidateType;
8158 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
8159 OverloadCandidateSet &CandidateSet;
8160
8161 static constexpr int ArithmeticTypesCap = 24;
8162 SmallVector<CanQualType, ArithmeticTypesCap> ArithmeticTypes;
8163
8164 // Define some indices used to iterate over the arithmetic types in
8165 // ArithmeticTypes. The "promoted arithmetic types" are the arithmetic
8166 // types are that preserved by promotion (C++ [over.built]p2).
8167 unsigned FirstIntegralType,
8168 LastIntegralType;
8169 unsigned FirstPromotedIntegralType,
8170 LastPromotedIntegralType;
8171 unsigned FirstPromotedArithmeticType,
8172 LastPromotedArithmeticType;
8173 unsigned NumArithmeticTypes;
8174
8175 void InitArithmeticTypes() {
8176 // Start of promoted types.
8177 FirstPromotedArithmeticType = 0;
8178 ArithmeticTypes.push_back(S.Context.FloatTy);
8179 ArithmeticTypes.push_back(S.Context.DoubleTy);
8180 ArithmeticTypes.push_back(S.Context.LongDoubleTy);
8181 if (S.Context.getTargetInfo().hasFloat128Type())
8182 ArithmeticTypes.push_back(S.Context.Float128Ty);
8183
8184 // Start of integral types.
8185 FirstIntegralType = ArithmeticTypes.size();
8186 FirstPromotedIntegralType = ArithmeticTypes.size();
8187 ArithmeticTypes.push_back(S.Context.IntTy);
8188 ArithmeticTypes.push_back(S.Context.LongTy);
8189 ArithmeticTypes.push_back(S.Context.LongLongTy);
8190 if (S.Context.getTargetInfo().hasInt128Type() ||
8191 (S.Context.getAuxTargetInfo() &&
8192 S.Context.getAuxTargetInfo()->hasInt128Type()))
8193 ArithmeticTypes.push_back(S.Context.Int128Ty);
8194 ArithmeticTypes.push_back(S.Context.UnsignedIntTy);
8195 ArithmeticTypes.push_back(S.Context.UnsignedLongTy);
8196 ArithmeticTypes.push_back(S.Context.UnsignedLongLongTy);
8197 if (S.Context.getTargetInfo().hasInt128Type() ||
8198 (S.Context.getAuxTargetInfo() &&
8199 S.Context.getAuxTargetInfo()->hasInt128Type()))
8200 ArithmeticTypes.push_back(S.Context.UnsignedInt128Ty);
8201 LastPromotedIntegralType = ArithmeticTypes.size();
8202 LastPromotedArithmeticType = ArithmeticTypes.size();
8203 // End of promoted types.
8204
8205 ArithmeticTypes.push_back(S.Context.BoolTy);
8206 ArithmeticTypes.push_back(S.Context.CharTy);
8207 ArithmeticTypes.push_back(S.Context.WCharTy);
8208 if (S.Context.getLangOpts().Char8)
8209 ArithmeticTypes.push_back(S.Context.Char8Ty);
8210 ArithmeticTypes.push_back(S.Context.Char16Ty);
8211 ArithmeticTypes.push_back(S.Context.Char32Ty);
8212 ArithmeticTypes.push_back(S.Context.SignedCharTy);
8213 ArithmeticTypes.push_back(S.Context.ShortTy);
8214 ArithmeticTypes.push_back(S.Context.UnsignedCharTy);
8215 ArithmeticTypes.push_back(S.Context.UnsignedShortTy);
8216 LastIntegralType = ArithmeticTypes.size();
8217 NumArithmeticTypes = ArithmeticTypes.size();
8218 // End of integral types.
8219 // FIXME: What about complex? What about half?
8220
8221 assert(ArithmeticTypes.size() <= ArithmeticTypesCap &&
8222 "Enough inline storage for all arithmetic types.");
8223 }
8224
8225 /// Helper method to factor out the common pattern of adding overloads
8226 /// for '++' and '--' builtin operators.
8227 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
8228 bool HasVolatile,
8229 bool HasRestrict) {
8230 QualType ParamTypes[2] = {
8231 S.Context.getLValueReferenceType(CandidateTy),
8232 S.Context.IntTy
8233 };
8234
8235 // Non-volatile version.
8236 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8237
8238 // Use a heuristic to reduce number of builtin candidates in the set:
8239 // add volatile version only if there are conversions to a volatile type.
8240 if (HasVolatile) {
8241 ParamTypes[0] =
8242 S.Context.getLValueReferenceType(
8243 S.Context.getVolatileType(CandidateTy));
8244 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8245 }
8246
8247 // Add restrict version only if there are conversions to a restrict type
8248 // and our candidate type is a non-restrict-qualified pointer.
8249 if (HasRestrict && CandidateTy->isAnyPointerType() &&
8250 !CandidateTy.isRestrictQualified()) {
8251 ParamTypes[0]
8252 = S.Context.getLValueReferenceType(
8253 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
8254 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8255
8256 if (HasVolatile) {
8257 ParamTypes[0]
8258 = S.Context.getLValueReferenceType(
8259 S.Context.getCVRQualifiedType(CandidateTy,
8260 (Qualifiers::Volatile |
8261 Qualifiers::Restrict)));
8262 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8263 }
8264 }
8265
8266 }
8267
8268 /// Helper to add an overload candidate for a binary builtin with types \p L
8269 /// and \p R.
8270 void AddCandidate(QualType L, QualType R) {
8271 QualType LandR[2] = {L, R};
8272 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8273 }
8274
8275public:
8276 BuiltinOperatorOverloadBuilder(
8277 Sema &S, ArrayRef<Expr *> Args,
8278 Qualifiers VisibleTypeConversionsQuals,
8279 bool HasArithmeticOrEnumeralCandidateType,
8280 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
8281 OverloadCandidateSet &CandidateSet)
8282 : S(S), Args(Args),
8283 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
8284 HasArithmeticOrEnumeralCandidateType(
8285 HasArithmeticOrEnumeralCandidateType),
8286 CandidateTypes(CandidateTypes),
8287 CandidateSet(CandidateSet) {
8288
8289 InitArithmeticTypes();
8290 }
8291
8292 // Increment is deprecated for bool since C++17.
8293 //
8294 // C++ [over.built]p3:
8295 //
8296 // For every pair (T, VQ), where T is an arithmetic type other
8297 // than bool, and VQ is either volatile or empty, there exist
8298 // candidate operator functions of the form
8299 //
8300 // VQ T& operator++(VQ T&);
8301 // T operator++(VQ T&, int);
8302 //
8303 // C++ [over.built]p4:
8304 //
8305 // For every pair (T, VQ), where T is an arithmetic type other
8306 // than bool, and VQ is either volatile or empty, there exist
8307 // candidate operator functions of the form
8308 //
8309 // VQ T& operator--(VQ T&);
8310 // T operator--(VQ T&, int);
8311 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
8312 if (!HasArithmeticOrEnumeralCandidateType)
8313 return;
8314
8315 for (unsigned Arith = 0; Arith < NumArithmeticTypes; ++Arith) {
8316 const auto TypeOfT = ArithmeticTypes[Arith];
8317 if (TypeOfT == S.Context.BoolTy) {
8318 if (Op == OO_MinusMinus)
8319 continue;
8320 if (Op == OO_PlusPlus && S.getLangOpts().CPlusPlus17)
8321 continue;
8322 }
8323 addPlusPlusMinusMinusStyleOverloads(
8324 TypeOfT,
8325 VisibleTypeConversionsQuals.hasVolatile(),
8326 VisibleTypeConversionsQuals.hasRestrict());
8327 }
8328 }
8329
8330 // C++ [over.built]p5:
8331 //
8332 // For every pair (T, VQ), where T is a cv-qualified or
8333 // cv-unqualified object type, and VQ is either volatile or
8334 // empty, there exist candidate operator functions of the form
8335 //
8336 // T*VQ& operator++(T*VQ&);
8337 // T*VQ& operator--(T*VQ&);
8338 // T* operator++(T*VQ&, int);
8339 // T* operator--(T*VQ&, int);
8340 void addPlusPlusMinusMinusPointerOverloads() {
8341 for (QualType PtrTy : CandidateTypes[0].pointer_types()) {
8342 // Skip pointer types that aren't pointers to object types.
8343 if (!PtrTy->getPointeeType()->isObjectType())
8344 continue;
8345
8346 addPlusPlusMinusMinusStyleOverloads(
8347 PtrTy,
8348 (!PtrTy.isVolatileQualified() &&
8349 VisibleTypeConversionsQuals.hasVolatile()),
8350 (!PtrTy.isRestrictQualified() &&
8351 VisibleTypeConversionsQuals.hasRestrict()));
8352 }
8353 }
8354
8355 // C++ [over.built]p6:
8356 // For every cv-qualified or cv-unqualified object type T, there
8357 // exist candidate operator functions of the form
8358 //
8359 // T& operator*(T*);
8360 //
8361 // C++ [over.built]p7:
8362 // For every function type T that does not have cv-qualifiers or a
8363 // ref-qualifier, there exist candidate operator functions of the form
8364 // T& operator*(T*);
8365 void addUnaryStarPointerOverloads() {
8366 for (QualType ParamTy : CandidateTypes[0].pointer_types()) {
8367 QualType PointeeTy = ParamTy->getPointeeType();
8368 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
8369 continue;
8370
8371 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
8372 if (Proto->getMethodQuals() || Proto->getRefQualifier())
8373 continue;
8374
8375 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
8376 }
8377 }
8378
8379 // C++ [over.built]p9:
8380 // For every promoted arithmetic type T, there exist candidate
8381 // operator functions of the form
8382 //
8383 // T operator+(T);
8384 // T operator-(T);
8385 void addUnaryPlusOrMinusArithmeticOverloads() {
8386 if (!HasArithmeticOrEnumeralCandidateType)
8387 return;
8388
8389 for (unsigned Arith = FirstPromotedArithmeticType;
8390 Arith < LastPromotedArithmeticType; ++Arith) {
8391 QualType ArithTy = ArithmeticTypes[Arith];
8392 S.AddBuiltinCandidate(&ArithTy, Args, CandidateSet);
8393 }
8394
8395 // Extension: We also add these operators for vector types.
8396 for (QualType VecTy : CandidateTypes[0].vector_types())
8397 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8398 }
8399
8400 // C++ [over.built]p8:
8401 // For every type T, there exist candidate operator functions of
8402 // the form
8403 //
8404 // T* operator+(T*);
8405 void addUnaryPlusPointerOverloads() {
8406 for (QualType ParamTy : CandidateTypes[0].pointer_types())
8407 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
8408 }
8409
8410 // C++ [over.built]p10:
8411 // For every promoted integral type T, there exist candidate
8412 // operator functions of the form
8413 //
8414 // T operator~(T);
8415 void addUnaryTildePromotedIntegralOverloads() {
8416 if (!HasArithmeticOrEnumeralCandidateType)
8417 return;
8418
8419 for (unsigned Int = FirstPromotedIntegralType;
8420 Int < LastPromotedIntegralType; ++Int) {
8421 QualType IntTy = ArithmeticTypes[Int];
8422 S.AddBuiltinCandidate(&IntTy, Args, CandidateSet);
8423 }
8424
8425 // Extension: We also add this operator for vector types.
8426 for (QualType VecTy : CandidateTypes[0].vector_types())
8427 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8428 }
8429
8430 // C++ [over.match.oper]p16:
8431 // For every pointer to member type T or type std::nullptr_t, there
8432 // exist candidate operator functions of the form
8433 //
8434 // bool operator==(T,T);
8435 // bool operator!=(T,T);
8436 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
8437 /// Set of (canonical) types that we've already handled.
8438 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8439
8440 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8441 for (QualType MemPtrTy : CandidateTypes[ArgIdx].member_pointer_types()) {
8442 // Don't add the same builtin candidate twice.
8443 if (!AddedTypes.insert(S.Context.getCanonicalType(MemPtrTy)).second)
8444 continue;
8445
8446 QualType ParamTypes[2] = {MemPtrTy, MemPtrTy};
8447 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8448 }
8449
8450 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
8451 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
8452 if (AddedTypes.insert(NullPtrTy).second) {
8453 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
8454 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8455 }
8456 }
8457 }
8458 }
8459
8460 // C++ [over.built]p15:
8461 //
8462 // For every T, where T is an enumeration type or a pointer type,
8463 // there exist candidate operator functions of the form
8464 //
8465 // bool operator<(T, T);
8466 // bool operator>(T, T);
8467 // bool operator<=(T, T);
8468 // bool operator>=(T, T);
8469 // bool operator==(T, T);
8470 // bool operator!=(T, T);
8471 // R operator<=>(T, T)
8472 void addGenericBinaryPointerOrEnumeralOverloads() {
8473 // C++ [over.match.oper]p3:
8474 // [...]the built-in candidates include all of the candidate operator
8475 // functions defined in 13.6 that, compared to the given operator, [...]
8476 // do not have the same parameter-type-list as any non-template non-member
8477 // candidate.
8478 //
8479 // Note that in practice, this only affects enumeration types because there
8480 // aren't any built-in candidates of record type, and a user-defined operator
8481 // must have an operand of record or enumeration type. Also, the only other
8482 // overloaded operator with enumeration arguments, operator=,
8483 // cannot be overloaded for enumeration types, so this is the only place
8484 // where we must suppress candidates like this.
8485 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
8486 UserDefinedBinaryOperators;
8487
8488 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8489 if (!CandidateTypes[ArgIdx].enumeration_types().empty()) {
8490 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
8491 CEnd = CandidateSet.end();
8492 C != CEnd; ++C) {
8493 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
8494 continue;
8495
8496 if (C->Function->isFunctionTemplateSpecialization())
8497 continue;
8498
8499 // We interpret "same parameter-type-list" as applying to the
8500 // "synthesized candidate, with the order of the two parameters
8501 // reversed", not to the original function.
8502 bool Reversed = C->isReversed();
8503 QualType FirstParamType = C->Function->getParamDecl(Reversed ? 1 : 0)
8504 ->getType()
8505 .getUnqualifiedType();
8506 QualType SecondParamType = C->Function->getParamDecl(Reversed ? 0 : 1)
8507 ->getType()
8508 .getUnqualifiedType();
8509
8510 // Skip if either parameter isn't of enumeral type.
8511 if (!FirstParamType->isEnumeralType() ||
8512 !SecondParamType->isEnumeralType())
8513 continue;
8514
8515 // Add this operator to the set of known user-defined operators.
8516 UserDefinedBinaryOperators.insert(
8517 std::make_pair(S.Context.getCanonicalType(FirstParamType),
8518 S.Context.getCanonicalType(SecondParamType)));
8519 }
8520 }
8521 }
8522
8523 /// Set of (canonical) types that we've already handled.
8524 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8525
8526 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8527 for (QualType PtrTy : CandidateTypes[ArgIdx].pointer_types()) {
8528 // Don't add the same builtin candidate twice.
8529 if (!AddedTypes.insert(S.Context.getCanonicalType(PtrTy)).second)
8530 continue;
8531
8532 QualType ParamTypes[2] = {PtrTy, PtrTy};
8533 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8534 }
8535 for (QualType EnumTy : CandidateTypes[ArgIdx].enumeration_types()) {
8536 CanQualType CanonType = S.Context.getCanonicalType(EnumTy);
8537
8538 // Don't add the same builtin candidate twice, or if a user defined
8539 // candidate exists.
8540 if (!AddedTypes.insert(CanonType).second ||
8541 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
8542 CanonType)))
8543 continue;
8544 QualType ParamTypes[2] = {EnumTy, EnumTy};
8545 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8546 }
8547 }
8548 }
8549
8550 // C++ [over.built]p13:
8551 //
8552 // For every cv-qualified or cv-unqualified object type T
8553 // there exist candidate operator functions of the form
8554 //
8555 // T* operator+(T*, ptrdiff_t);
8556 // T& operator[](T*, ptrdiff_t); [BELOW]
8557 // T* operator-(T*, ptrdiff_t);
8558 // T* operator+(ptrdiff_t, T*);
8559 // T& operator[](ptrdiff_t, T*); [BELOW]
8560 //
8561 // C++ [over.built]p14:
8562 //
8563 // For every T, where T is a pointer to object type, there
8564 // exist candidate operator functions of the form
8565 //
8566 // ptrdiff_t operator-(T, T);
8567 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
8568 /// Set of (canonical) types that we've already handled.
8569 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8570
8571 for (int Arg = 0; Arg < 2; ++Arg) {
8572 QualType AsymmetricParamTypes[2] = {
8573 S.Context.getPointerDiffType(),
8574 S.Context.getPointerDiffType(),
8575 };
8576 for (QualType PtrTy : CandidateTypes[Arg].pointer_types()) {
8577 QualType PointeeTy = PtrTy->getPointeeType();
8578 if (!PointeeTy->isObjectType())
8579 continue;
8580
8581 AsymmetricParamTypes[Arg] = PtrTy;
8582 if (Arg == 0 || Op == OO_Plus) {
8583 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
8584 // T* operator+(ptrdiff_t, T*);
8585 S.AddBuiltinCandidate(AsymmetricParamTypes, Args, CandidateSet);
8586 }
8587 if (Op == OO_Minus) {
8588 // ptrdiff_t operator-(T, T);
8589 if (!AddedTypes.insert(S.Context.getCanonicalType(PtrTy)).second)
8590 continue;
8591
8592 QualType ParamTypes[2] = {PtrTy, PtrTy};
8593 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8594 }
8595 }
8596 }
8597 }
8598
8599 // C++ [over.built]p12:
8600 //
8601 // For every pair of promoted arithmetic types L and R, there
8602 // exist candidate operator functions of the form
8603 //
8604 // LR operator*(L, R);
8605 // LR operator/(L, R);
8606 // LR operator+(L, R);
8607 // LR operator-(L, R);
8608 // bool operator<(L, R);
8609 // bool operator>(L, R);
8610 // bool operator<=(L, R);
8611 // bool operator>=(L, R);
8612 // bool operator==(L, R);
8613 // bool operator!=(L, R);
8614 //
8615 // where LR is the result of the usual arithmetic conversions
8616 // between types L and R.
8617 //
8618 // C++ [over.built]p24:
8619 //
8620 // For every pair of promoted arithmetic types L and R, there exist
8621 // candidate operator functions of the form
8622 //
8623 // LR operator?(bool, L, R);
8624 //
8625 // where LR is the result of the usual arithmetic conversions
8626 // between types L and R.
8627 // Our candidates ignore the first parameter.
8628 void addGenericBinaryArithmeticOverloads() {
8629 if (!HasArithmeticOrEnumeralCandidateType)
8630 return;
8631
8632 for (unsigned Left = FirstPromotedArithmeticType;
8633 Left < LastPromotedArithmeticType; ++Left) {
8634 for (unsigned Right = FirstPromotedArithmeticType;
8635 Right < LastPromotedArithmeticType; ++Right) {
8636 QualType LandR[2] = { ArithmeticTypes[Left],
8637 ArithmeticTypes[Right] };
8638 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8639 }
8640 }
8641
8642 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
8643 // conditional operator for vector types.
8644 for (QualType Vec1Ty : CandidateTypes[0].vector_types())
8645 for (QualType Vec2Ty : CandidateTypes[1].vector_types()) {
8646 QualType LandR[2] = {Vec1Ty, Vec2Ty};
8647 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8648 }
8649 }
8650
8651 /// Add binary operator overloads for each candidate matrix type M1, M2:
8652 /// * (M1, M1) -> M1
8653 /// * (M1, M1.getElementType()) -> M1
8654 /// * (M2.getElementType(), M2) -> M2
8655 /// * (M2, M2) -> M2 // Only if M2 is not part of CandidateTypes[0].
8656 void addMatrixBinaryArithmeticOverloads() {
8657 if (!HasArithmeticOrEnumeralCandidateType)
8658 return;
8659
8660 for (QualType M1 : CandidateTypes[0].matrix_types()) {
8661 AddCandidate(M1, cast<MatrixType>(M1)->getElementType());
8662 AddCandidate(M1, M1);
8663 }
8664
8665 for (QualType M2 : CandidateTypes[1].matrix_types()) {
8666 AddCandidate(cast<MatrixType>(M2)->getElementType(), M2);
8667 if (!CandidateTypes[0].containsMatrixType(M2))
8668 AddCandidate(M2, M2);
8669 }
8670 }
8671
8672 // C++2a [over.built]p14:
8673 //
8674 // For every integral type T there exists a candidate operator function
8675 // of the form
8676 //
8677 // std::strong_ordering operator<=>(T, T)
8678 //
8679 // C++2a [over.built]p15:
8680 //
8681 // For every pair of floating-point types L and R, there exists a candidate
8682 // operator function of the form
8683 //
8684 // std::partial_ordering operator<=>(L, R);
8685 //
8686 // FIXME: The current specification for integral types doesn't play nice with
8687 // the direction of p0946r0, which allows mixed integral and unscoped-enum
8688 // comparisons. Under the current spec this can lead to ambiguity during
8689 // overload resolution. For example:
8690 //
8691 // enum A : int {a};
8692 // auto x = (a <=> (long)42);
8693 //
8694 // error: call is ambiguous for arguments 'A' and 'long'.
8695 // note: candidate operator<=>(int, int)
8696 // note: candidate operator<=>(long, long)
8697 //
8698 // To avoid this error, this function deviates from the specification and adds
8699 // the mixed overloads `operator<=>(L, R)` where L and R are promoted
8700 // arithmetic types (the same as the generic relational overloads).
8701 //
8702 // For now this function acts as a placeholder.
8703 void addThreeWayArithmeticOverloads() {
8704 addGenericBinaryArithmeticOverloads();
8705 }
8706
8707 // C++ [over.built]p17:
8708 //
8709 // For every pair of promoted integral types L and R, there
8710 // exist candidate operator functions of the form
8711 //
8712 // LR operator%(L, R);
8713 // LR operator&(L, R);
8714 // LR operator^(L, R);
8715 // LR operator|(L, R);
8716 // L operator<<(L, R);
8717 // L operator>>(L, R);
8718 //
8719 // where LR is the result of the usual arithmetic conversions
8720 // between types L and R.
8721 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
8722 if (!HasArithmeticOrEnumeralCandidateType)
8723 return;
8724
8725 for (unsigned Left = FirstPromotedIntegralType;
8726 Left < LastPromotedIntegralType; ++Left) {
8727 for (unsigned Right = FirstPromotedIntegralType;
8728 Right < LastPromotedIntegralType; ++Right) {
8729 QualType LandR[2] = { ArithmeticTypes[Left],
8730 ArithmeticTypes[Right] };
8731 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8732 }
8733 }
8734 }
8735
8736 // C++ [over.built]p20:
8737 //
8738 // For every pair (T, VQ), where T is an enumeration or
8739 // pointer to member type and VQ is either volatile or
8740 // empty, there exist candidate operator functions of the form
8741 //
8742 // VQ T& operator=(VQ T&, T);
8743 void addAssignmentMemberPointerOrEnumeralOverloads() {
8744 /// Set of (canonical) types that we've already handled.
8745 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8746
8747 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8748 for (QualType EnumTy : CandidateTypes[ArgIdx].enumeration_types()) {
8749 if (!AddedTypes.insert(S.Context.getCanonicalType(EnumTy)).second)
8750 continue;
8751
8752 AddBuiltinAssignmentOperatorCandidates(S, EnumTy, Args, CandidateSet);
8753 }
8754
8755 for (QualType MemPtrTy : CandidateTypes[ArgIdx].member_pointer_types()) {
8756 if (!AddedTypes.insert(S.Context.getCanonicalType(MemPtrTy)).second)
8757 continue;
8758
8759 AddBuiltinAssignmentOperatorCandidates(S, MemPtrTy, Args, CandidateSet);
8760 }
8761 }
8762 }
8763
8764 // C++ [over.built]p19:
8765 //
8766 // For every pair (T, VQ), where T is any type and VQ is either
8767 // volatile or empty, there exist candidate operator functions
8768 // of the form
8769 //
8770 // T*VQ& operator=(T*VQ&, T*);
8771 //
8772 // C++ [over.built]p21:
8773 //
8774 // For every pair (T, VQ), where T is a cv-qualified or
8775 // cv-unqualified object type and VQ is either volatile or
8776 // empty, there exist candidate operator functions of the form
8777 //
8778 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
8779 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
8780 void addAssignmentPointerOverloads(bool isEqualOp) {
8781 /// Set of (canonical) types that we've already handled.
8782 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8783
8784 for (QualType PtrTy : CandidateTypes[0].pointer_types()) {
8785 // If this is operator=, keep track of the builtin candidates we added.
8786 if (isEqualOp)
8787 AddedTypes.insert(S.Context.getCanonicalType(PtrTy));
8788 else if (!PtrTy->getPointeeType()->isObjectType())
8789 continue;
8790
8791 // non-volatile version
8792 QualType ParamTypes[2] = {
8793 S.Context.getLValueReferenceType(PtrTy),
8794 isEqualOp ? PtrTy : S.Context.getPointerDiffType(),
8795 };
8796 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8797 /*IsAssignmentOperator=*/ isEqualOp);
8798
8799 bool NeedVolatile = !PtrTy.isVolatileQualified() &&
8800 VisibleTypeConversionsQuals.hasVolatile();
8801 if (NeedVolatile) {
8802 // volatile version
8803 ParamTypes[0] =
8804 S.Context.getLValueReferenceType(S.Context.getVolatileType(PtrTy));
8805 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8806 /*IsAssignmentOperator=*/isEqualOp);
8807 }
8808
8809 if (!PtrTy.isRestrictQualified() &&
8810 VisibleTypeConversionsQuals.hasRestrict()) {
8811 // restrict version
8812 ParamTypes[0] =
8813 S.Context.getLValueReferenceType(S.Context.getRestrictType(PtrTy));
8814 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8815 /*IsAssignmentOperator=*/isEqualOp);
8816
8817 if (NeedVolatile) {
8818 // volatile restrict version
8819 ParamTypes[0] =
8820 S.Context.getLValueReferenceType(S.Context.getCVRQualifiedType(
8821 PtrTy, (Qualifiers::Volatile | Qualifiers::Restrict)));
8822 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8823 /*IsAssignmentOperator=*/isEqualOp);
8824 }
8825 }
8826 }
8827
8828 if (isEqualOp) {
8829 for (QualType PtrTy : CandidateTypes[1].pointer_types()) {
8830 // Make sure we don't add the same candidate twice.
8831 if (!AddedTypes.insert(S.Context.getCanonicalType(PtrTy)).second)
8832 continue;
8833
8834 QualType ParamTypes[2] = {
8835 S.Context.getLValueReferenceType(PtrTy),
8836 PtrTy,
8837 };
8838
8839 // non-volatile version
8840 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8841 /*IsAssignmentOperator=*/true);
8842
8843 bool NeedVolatile = !PtrTy.isVolatileQualified() &&
8844 VisibleTypeConversionsQuals.hasVolatile();
8845 if (NeedVolatile) {
8846 // volatile version
8847 ParamTypes[0] = S.Context.getLValueReferenceType(
8848 S.Context.getVolatileType(PtrTy));
8849 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8850 /*IsAssignmentOperator=*/true);
8851 }
8852
8853 if (!PtrTy.isRestrictQualified() &&
8854 VisibleTypeConversionsQuals.hasRestrict()) {
8855 // restrict version
8856 ParamTypes[0] = S.Context.getLValueReferenceType(
8857 S.Context.getRestrictType(PtrTy));
8858 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8859 /*IsAssignmentOperator=*/true);
8860
8861 if (NeedVolatile) {
8862 // volatile restrict version
8863 ParamTypes[0] =
8864 S.Context.getLValueReferenceType(S.Context.getCVRQualifiedType(
8865 PtrTy, (Qualifiers::Volatile | Qualifiers::Restrict)));
8866 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8867 /*IsAssignmentOperator=*/true);
8868 }
8869 }
8870 }
8871 }
8872 }
8873
8874 // C++ [over.built]p18:
8875 //
8876 // For every triple (L, VQ, R), where L is an arithmetic type,
8877 // VQ is either volatile or empty, and R is a promoted
8878 // arithmetic type, there exist candidate operator functions of
8879 // the form
8880 //
8881 // VQ L& operator=(VQ L&, R);
8882 // VQ L& operator*=(VQ L&, R);
8883 // VQ L& operator/=(VQ L&, R);
8884 // VQ L& operator+=(VQ L&, R);
8885 // VQ L& operator-=(VQ L&, R);
8886 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8887 if (!HasArithmeticOrEnumeralCandidateType)
8888 return;
8889
8890 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8891 for (unsigned Right = FirstPromotedArithmeticType;
8892 Right < LastPromotedArithmeticType; ++Right) {
8893 QualType ParamTypes[2];
8894 ParamTypes[1] = ArithmeticTypes[Right];
8895 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8896 S, ArithmeticTypes[Left], Args[0]);
8897 // Add this built-in operator as a candidate (VQ is empty).
8898 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8899 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8900 /*IsAssignmentOperator=*/isEqualOp);
8901
8902 // Add this built-in operator as a candidate (VQ is 'volatile').
8903 if (VisibleTypeConversionsQuals.hasVolatile()) {
8904 ParamTypes[0] = S.Context.getVolatileType(LeftBaseTy);
8905 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8906 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8907 /*IsAssignmentOperator=*/isEqualOp);
8908 }
8909 }
8910 }
8911
8912 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8913 for (QualType Vec1Ty : CandidateTypes[0].vector_types())
8914 for (QualType Vec2Ty : CandidateTypes[0].vector_types()) {
8915 QualType ParamTypes[2];
8916 ParamTypes[1] = Vec2Ty;
8917 // Add this built-in operator as a candidate (VQ is empty).
8918 ParamTypes[0] = S.Context.getLValueReferenceType(Vec1Ty);
8919 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8920 /*IsAssignmentOperator=*/isEqualOp);
8921
8922 // Add this built-in operator as a candidate (VQ is 'volatile').
8923 if (VisibleTypeConversionsQuals.hasVolatile()) {
8924 ParamTypes[0] = S.Context.getVolatileType(Vec1Ty);
8925 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8926 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8927 /*IsAssignmentOperator=*/isEqualOp);
8928 }
8929 }
8930 }
8931
8932 // C++ [over.built]p22:
8933 //
8934 // For every triple (L, VQ, R), where L is an integral type, VQ
8935 // is either volatile or empty, and R is a promoted integral
8936 // type, there exist candidate operator functions of the form
8937 //
8938 // VQ L& operator%=(VQ L&, R);
8939 // VQ L& operator<<=(VQ L&, R);
8940 // VQ L& operator>>=(VQ L&, R);
8941 // VQ L& operator&=(VQ L&, R);
8942 // VQ L& operator^=(VQ L&, R);
8943 // VQ L& operator|=(VQ L&, R);
8944 void addAssignmentIntegralOverloads() {
8945 if (!HasArithmeticOrEnumeralCandidateType)
8946 return;
8947
8948 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8949 for (unsigned Right = FirstPromotedIntegralType;
8950 Right < LastPromotedIntegralType; ++Right) {
8951 QualType ParamTypes[2];
8952 ParamTypes[1] = ArithmeticTypes[Right];
8953 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8954 S, ArithmeticTypes[Left], Args[0]);
8955 // Add this built-in operator as a candidate (VQ is empty).
8956 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8957 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8958 if (VisibleTypeConversionsQuals.hasVolatile()) {
8959 // Add this built-in operator as a candidate (VQ is 'volatile').
8960 ParamTypes[0] = LeftBaseTy;
8961 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8962 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8963 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8964 }
8965 }
8966 }
8967 }
8968
8969 // C++ [over.operator]p23:
8970 //
8971 // There also exist candidate operator functions of the form
8972 //
8973 // bool operator!(bool);
8974 // bool operator&&(bool, bool);
8975 // bool operator||(bool, bool);
8976 void addExclaimOverload() {
8977 QualType ParamTy = S.Context.BoolTy;
8978 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet,
8979 /*IsAssignmentOperator=*/false,
8980 /*NumContextualBoolArguments=*/1);
8981 }
8982 void addAmpAmpOrPipePipeOverload() {
8983 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8984 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8985 /*IsAssignmentOperator=*/false,
8986 /*NumContextualBoolArguments=*/2);
8987 }
8988
8989 // C++ [over.built]p13:
8990 //
8991 // For every cv-qualified or cv-unqualified object type T there
8992 // exist candidate operator functions of the form
8993 //
8994 // T* operator+(T*, ptrdiff_t); [ABOVE]
8995 // T& operator[](T*, ptrdiff_t);
8996 // T* operator-(T*, ptrdiff_t); [ABOVE]
8997 // T* operator+(ptrdiff_t, T*); [ABOVE]
8998 // T& operator[](ptrdiff_t, T*);
8999 void addSubscriptOverloads() {
9000 for (QualType PtrTy : CandidateTypes[0].pointer_types()) {
9001 QualType ParamTypes[2] = {PtrTy, S.Context.getPointerDiffType()};
9002 QualType PointeeType = PtrTy->getPointeeType();
9003 if (!PointeeType->isObjectType())
9004 continue;
9005
9006 // T& operator[](T*, ptrdiff_t)
9007 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9008 }
9009
9010 for (QualType PtrTy : CandidateTypes[1].pointer_types()) {
9011 QualType ParamTypes[2] = {S.Context.getPointerDiffType(), PtrTy};
9012 QualType PointeeType = PtrTy->getPointeeType();
9013 if (!PointeeType->isObjectType())
9014 continue;
9015
9016 // T& operator[](ptrdiff_t, T*)
9017 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9018 }
9019 }
9020
9021 // C++ [over.built]p11:
9022 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
9023 // C1 is the same type as C2 or is a derived class of C2, T is an object
9024 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
9025 // there exist candidate operator functions of the form
9026 //
9027 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
9028 //
9029 // where CV12 is the union of CV1 and CV2.
9030 void addArrowStarOverloads() {
9031 for (QualType PtrTy : CandidateTypes[0].pointer_types()) {
9032 QualType C1Ty = PtrTy;
9033 QualType C1;
9034 QualifierCollector Q1;
9035 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
9036 if (!isa<RecordType>(C1))
9037 continue;
9038 // heuristic to reduce number of builtin candidates in the set.
9039 // Add volatile/restrict version only if there are conversions to a
9040 // volatile/restrict type.
9041 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
9042 continue;
9043 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
9044 continue;
9045 for (QualType MemPtrTy : CandidateTypes[1].member_pointer_types()) {
9046 const MemberPointerType *mptr = cast<MemberPointerType>(MemPtrTy);
9047 QualType C2 = QualType(mptr->getClass(), 0);
9048 C2 = C2.getUnqualifiedType();
9049 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
9050 break;
9051 QualType ParamTypes[2] = {PtrTy, MemPtrTy};
9052 // build CV12 T&
9053 QualType T = mptr->getPointeeType();
9054 if (!VisibleTypeConversionsQuals.hasVolatile() &&
9055 T.isVolatileQualified())
9056 continue;
9057 if (!VisibleTypeConversionsQuals.hasRestrict() &&
9058 T.isRestrictQualified())
9059 continue;
9060 T = Q1.apply(S.Context, T);
9061 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9062 }
9063 }
9064 }
9065
9066 // Note that we don't consider the first argument, since it has been
9067 // contextually converted to bool long ago. The candidates below are
9068 // therefore added as binary.
9069 //
9070 // C++ [over.built]p25:
9071 // For every type T, where T is a pointer, pointer-to-member, or scoped
9072 // enumeration type, there exist candidate operator functions of the form
9073 //
9074 // T operator?(bool, T, T);
9075 //
9076 void addConditionalOperatorOverloads() {
9077 /// Set of (canonical) types that we've already handled.
9078 llvm::SmallPtrSet<QualType, 8> AddedTypes;
9079
9080 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
9081 for (QualType PtrTy : CandidateTypes[ArgIdx].pointer_types()) {
9082 if (!AddedTypes.insert(S.Context.getCanonicalType(PtrTy)).second)
9083 continue;
9084
9085 QualType ParamTypes[2] = {PtrTy, PtrTy};
9086 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9087 }
9088
9089 for (QualType MemPtrTy : CandidateTypes[ArgIdx].member_pointer_types()) {
9090 if (!AddedTypes.insert(S.Context.getCanonicalType(MemPtrTy)).second)
9091 continue;
9092
9093 QualType ParamTypes[2] = {MemPtrTy, MemPtrTy};
9094 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9095 }
9096
9097 if (S.getLangOpts().CPlusPlus11) {
9098 for (QualType EnumTy : CandidateTypes[ArgIdx].enumeration_types()) {
9099 if (!EnumTy->castAs<EnumType>()->getDecl()->isScoped())
9100 continue;
9101
9102 if (!AddedTypes.insert(S.Context.getCanonicalType(EnumTy)).second)
9103 continue;
9104
9105 QualType ParamTypes[2] = {EnumTy, EnumTy};
9106 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9107 }
9108 }
9109 }
9110 }
9111};
9112
9113} // end anonymous namespace
9114
9115/// AddBuiltinOperatorCandidates - Add the appropriate built-in
9116/// operator overloads to the candidate set (C++ [over.built]), based
9117/// on the operator @p Op and the arguments given. For example, if the
9118/// operator is a binary '+', this routine might add "int
9119/// operator+(int, int)" to cover integer addition.
9120void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
9121 SourceLocation OpLoc,
9122 ArrayRef<Expr *> Args,
9123 OverloadCandidateSet &CandidateSet) {
9124 // Find all of the types that the arguments can convert to, but only
9125 // if the operator we're looking at has built-in operator candidates
9126 // that make use of these types. Also record whether we encounter non-record
9127 // candidate types or either arithmetic or enumeral candidate types.
9128 Qualifiers VisibleTypeConversionsQuals;
9129 VisibleTypeConversionsQuals.addConst();
9130 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
9131 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
9132
9133 bool HasNonRecordCandidateType = false;
9134 bool HasArithmeticOrEnumeralCandidateType = false;
9135 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
9136 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
9137 CandidateTypes.emplace_back(*this);
9138 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
9139 OpLoc,
9140 true,
9141 (Op == OO_Exclaim ||
9142 Op == OO_AmpAmp ||
9143 Op == OO_PipePipe),
9144 VisibleTypeConversionsQuals);
9145 HasNonRecordCandidateType = HasNonRecordCandidateType ||
9146 CandidateTypes[ArgIdx].hasNonRecordTypes();
9147 HasArithmeticOrEnumeralCandidateType =
9148 HasArithmeticOrEnumeralCandidateType ||
9149 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
9150 }
9151
9152 // Exit early when no non-record types have been added to the candidate set
9153 // for any of the arguments to the operator.
9154 //
9155 // We can't exit early for !, ||, or &&, since there we have always have
9156 // 'bool' overloads.
9157 if (!HasNonRecordCandidateType &&
9158 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
9159 return;
9160
9161 // Setup an object to manage the common state for building overloads.
9162 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
9163 VisibleTypeConversionsQuals,
9164 HasArithmeticOrEnumeralCandidateType,
9165 CandidateTypes, CandidateSet);
9166
9167 // Dispatch over the operation to add in only those overloads which apply.
9168 switch (Op) {
9169 case OO_None:
9170 case NUM_OVERLOADED_OPERATORS:
9171 llvm_unreachable("Expected an overloaded operator");
9172
9173 case OO_New:
9174 case OO_Delete:
9175 case OO_Array_New:
9176 case OO_Array_Delete:
9177 case OO_Call:
9178 llvm_unreachable(
9179 "Special operators don't use AddBuiltinOperatorCandidates");
9180
9181 case OO_Comma:
9182 case OO_Arrow:
9183 case OO_Coawait:
9184 // C++ [over.match.oper]p3:
9185 // -- For the operator ',', the unary operator '&', the
9186 // operator '->', or the operator 'co_await', the
9187 // built-in candidates set is empty.
9188 break;
9189
9190 case OO_Plus: // '+' is either unary or binary
9191 if (Args.size() == 1)
9192 OpBuilder.addUnaryPlusPointerOverloads();
9193 LLVM_FALLTHROUGH;
9194
9195 case OO_Minus: // '-' is either unary or binary
9196 if (Args.size() == 1) {
9197 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
9198 } else {
9199 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
9200 OpBuilder.addGenericBinaryArithmeticOverloads();
9201 OpBuilder.addMatrixBinaryArithmeticOverloads();
9202 }
9203 break;
9204
9205 case OO_Star: // '*' is either unary or binary
9206 if (Args.size() == 1)
9207 OpBuilder.addUnaryStarPointerOverloads();
9208 else {
9209 OpBuilder.addGenericBinaryArithmeticOverloads();
9210 OpBuilder.addMatrixBinaryArithmeticOverloads();
9211 }
9212 break;
9213
9214 case OO_Slash:
9215 OpBuilder.addGenericBinaryArithmeticOverloads();
9216 break;
9217
9218 case OO_PlusPlus:
9219 case OO_MinusMinus:
9220 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
9221 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
9222 break;
9223
9224 case OO_EqualEqual:
9225 case OO_ExclaimEqual:
9226 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
9227 LLVM_FALLTHROUGH;
9228
9229 case OO_Less:
9230 case OO_Greater:
9231 case OO_LessEqual:
9232 case OO_GreaterEqual:
9233 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
9234 OpBuilder.addGenericBinaryArithmeticOverloads();
9235 break;
9236
9237 case OO_Spaceship:
9238 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
9239 OpBuilder.addThreeWayArithmeticOverloads();
9240 break;
9241
9242 case OO_Percent:
9243 case OO_Caret:
9244 case OO_Pipe:
9245 case OO_LessLess:
9246 case OO_GreaterGreater:
9247 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
9248 break;
9249
9250 case OO_Amp: // '&' is either unary or binary
9251 if (Args.size() == 1)
9252 // C++ [over.match.oper]p3:
9253 // -- For the operator ',', the unary operator '&', or the
9254 // operator '->', the built-in candidates set is empty.
9255 break;
9256
9257 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
9258 break;
9259
9260 case OO_Tilde:
9261 OpBuilder.addUnaryTildePromotedIntegralOverloads();
9262 break;
9263
9264 case OO_Equal:
9265 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
9266 LLVM_FALLTHROUGH;
9267
9268 case OO_PlusEqual:
9269 case OO_MinusEqual:
9270 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
9271 LLVM_FALLTHROUGH;
9272
9273 case OO_StarEqual:
9274 case OO_SlashEqual:
9275 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
9276 break;
9277
9278 case OO_PercentEqual:
9279 case OO_LessLessEqual:
9280 case OO_GreaterGreaterEqual:
9281 case OO_AmpEqual:
9282 case OO_CaretEqual:
9283 case OO_PipeEqual:
9284 OpBuilder.addAssignmentIntegralOverloads();
9285 break;
9286
9287 case OO_Exclaim:
9288 OpBuilder.addExclaimOverload();
9289 break;
9290
9291 case OO_AmpAmp:
9292 case OO_PipePipe:
9293 OpBuilder.addAmpAmpOrPipePipeOverload();
9294 break;
9295
9296 case OO_Subscript:
9297 OpBuilder.addSubscriptOverloads();
9298 break;
9299
9300 case OO_ArrowStar:
9301 OpBuilder.addArrowStarOverloads();
9302 break;
9303
9304 case OO_Conditional:
9305 OpBuilder.addConditionalOperatorOverloads();
9306 OpBuilder.addGenericBinaryArithmeticOverloads();
9307 break;
9308 }
9309}
9310
9311/// Add function candidates found via argument-dependent lookup
9312/// to the set of overloading candidates.
9313///
9314/// This routine performs argument-dependent name lookup based on the
9315/// given function name (which may also be an operator name) and adds
9316/// all of the overload candidates found by ADL to the overload
9317/// candidate set (C++ [basic.lookup.argdep]).
9318void
9319Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
9320 SourceLocation Loc,
9321 ArrayRef<Expr *> Args,
9322 TemplateArgumentListInfo *ExplicitTemplateArgs,
9323 OverloadCandidateSet& CandidateSet,
9324 bool PartialOverloading) {
9325 ADLResult Fns;
9326
9327 // FIXME: This approach for uniquing ADL results (and removing
9328 // redundant candidates from the set) relies on pointer-equality,
9329 // which means we need to key off the canonical decl. However,
9330 // always going back to the canonical decl might not get us the
9331 // right set of default arguments. What default arguments are
9332 // we supposed to consider on ADL candidates, anyway?
9333
9334 // FIXME: Pass in the explicit template arguments?
9335 ArgumentDependentLookup(Name, Loc, Args, Fns);
9336
9337 // Erase all of the candidates we already knew about.
9338 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
9339 CandEnd = CandidateSet.end();
9340 Cand != CandEnd; ++Cand)
9341 if (Cand->Function) {
9342 Fns.erase(Cand->Function);
9343 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
9344 Fns.erase(FunTmpl);
9345 }
9346
9347 // For each of the ADL candidates we found, add it to the overload
9348 // set.
9349 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
9350 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
9351
9352 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
9353 if (ExplicitTemplateArgs)
9354 continue;
9355
9356 AddOverloadCandidate(
9357 FD, FoundDecl, Args, CandidateSet, /*SuppressUserConversions=*/false,
9358 PartialOverloading, /*AllowExplicit=*/true,
9359 /*AllowExplicitConversions=*/false, ADLCallKind::UsesADL);
9360 if (CandidateSet.getRewriteInfo().shouldAddReversed(Context, FD)) {
9361 AddOverloadCandidate(
9362 FD, FoundDecl, {Args[1], Args[0]}, CandidateSet,
9363 /*SuppressUserConversions=*/false, PartialOverloading,
9364 /*AllowExplicit=*/true, /*AllowExplicitConversions=*/false,
9365 ADLCallKind::UsesADL, None, OverloadCandidateParamOrder::Reversed);
9366 }
9367 } else {
9368 auto *FTD = cast<FunctionTemplateDecl>(*I);
9369 AddTemplateOverloadCandidate(
9370 FTD, FoundDecl, ExplicitTemplateArgs, Args, CandidateSet,
9371 /*SuppressUserConversions=*/false, PartialOverloading,
9372 /*AllowExplicit=*/true, ADLCallKind::UsesADL);
9373 if (CandidateSet.getRewriteInfo().shouldAddReversed(
9374 Context, FTD->getTemplatedDecl())) {
9375 AddTemplateOverloadCandidate(
9376 FTD, FoundDecl, ExplicitTemplateArgs, {Args[1], Args[0]},
9377 CandidateSet, /*SuppressUserConversions=*/false, PartialOverloading,
9378 /*AllowExplicit=*/true, ADLCallKind::UsesADL,
9379 OverloadCandidateParamOrder::Reversed);
9380 }
9381 }
9382 }
9383}
9384
9385namespace {
9386enum class Comparison { Equal, Better, Worse };
9387}
9388
9389/// Compares the enable_if attributes of two FunctionDecls, for the purposes of
9390/// overload resolution.
9391///
9392/// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
9393/// Cand1's first N enable_if attributes have precisely the same conditions as
9394/// Cand2's first N enable_if attributes (where N = the number of enable_if
9395/// attributes on Cand2), and Cand1 has more than N enable_if attributes.
9396///
9397/// Note that you can have a pair of candidates such that Cand1's enable_if
9398/// attributes are worse than Cand2's, and Cand2's enable_if attributes are
9399/// worse than Cand1's.
9400static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
9401 const FunctionDecl *Cand2) {
9402 // Common case: One (or both) decls don't have enable_if attrs.
9403 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
9404 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
9405 if (!Cand1Attr || !Cand2Attr) {
9406 if (Cand1Attr == Cand2Attr)
9407 return Comparison::Equal;
9408 return Cand1Attr ? Comparison::Better : Comparison::Worse;
9409 }
9410
9411 auto Cand1Attrs = Cand1->specific_attrs<EnableIfAttr>();
9412 auto Cand2Attrs = Cand2->specific_attrs<EnableIfAttr>();
9413
9414 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
9415 for (auto Pair : zip_longest(Cand1Attrs, Cand2Attrs)) {
9416 Optional<EnableIfAttr *> Cand1A = std::get<0>(Pair);
9417 Optional<EnableIfAttr *> Cand2A = std::get<1>(Pair);
9418
9419 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
9420 // has fewer enable_if attributes than Cand2, and vice versa.
9421 if (!Cand1A)
9422 return Comparison::Worse;
9423 if (!Cand2A)
9424 return Comparison::Better;
9425
9426 Cand1ID.clear();
9427 Cand2ID.clear();
9428
9429 (*Cand1A)->getCond()->Profile(Cand1ID, S.getASTContext(), true);
9430 (*Cand2A)->getCond()->Profile(Cand2ID, S.getASTContext(), true);
9431 if (Cand1ID != Cand2ID)
9432 return Comparison::Worse;
9433 }
9434
9435 return Comparison::Equal;
9436}
9437
9438static Comparison
9439isBetterMultiversionCandidate(const OverloadCandidate &Cand1,
9440 const OverloadCandidate &Cand2) {
9441 if (!Cand1.Function || !Cand1.Function->isMultiVersion() || !Cand2.Function ||
9442 !Cand2.Function->isMultiVersion())
9443 return Comparison::Equal;
9444
9445 // If both are invalid, they are equal. If one of them is invalid, the other
9446 // is better.
9447 if (Cand1.Function->isInvalidDecl()) {
9448 if (Cand2.Function->isInvalidDecl())
9449 return Comparison::Equal;
9450 return Comparison::Worse;
9451 }
9452 if (Cand2.Function->isInvalidDecl())
9453 return Comparison::Better;
9454
9455 // If this is a cpu_dispatch/cpu_specific multiversion situation, prefer
9456 // cpu_dispatch, else arbitrarily based on the identifiers.
9457 bool Cand1CPUDisp = Cand1.Function->hasAttr<CPUDispatchAttr>();
9458 bool Cand2CPUDisp = Cand2.Function->hasAttr<CPUDispatchAttr>();
9459 const auto *Cand1CPUSpec = Cand1.Function->getAttr<CPUSpecificAttr>();
9460 const auto *Cand2CPUSpec = Cand2.Function->getAttr<CPUSpecificAttr>();
9461
9462 if (!Cand1CPUDisp && !Cand2CPUDisp && !Cand1CPUSpec && !Cand2CPUSpec)
9463 return Comparison::Equal;
9464
9465 if (Cand1CPUDisp && !Cand2CPUDisp)
9466 return Comparison::Better;
9467 if (Cand2CPUDisp && !Cand1CPUDisp)
9468 return Comparison::Worse;
9469
9470 if (Cand1CPUSpec && Cand2CPUSpec) {
9471 if (Cand1CPUSpec->cpus_size() != Cand2CPUSpec->cpus_size())
9472 return Cand1CPUSpec->cpus_size() < Cand2CPUSpec->cpus_size()
9473 ? Comparison::Better
9474 : Comparison::Worse;
9475
9476 std::pair<CPUSpecificAttr::cpus_iterator, CPUSpecificAttr::cpus_iterator>
9477 FirstDiff = std::mismatch(
9478 Cand1CPUSpec->cpus_begin(), Cand1CPUSpec->cpus_end(),
9479 Cand2CPUSpec->cpus_begin(),
9480 [](const IdentifierInfo *LHS, const IdentifierInfo *RHS) {
9481 return LHS->getName() == RHS->getName();
9482 });
9483
9484 assert(FirstDiff.first != Cand1CPUSpec->cpus_end() &&
9485 "Two different cpu-specific versions should not have the same "
9486 "identifier list, otherwise they'd be the same decl!");
9487 return (*FirstDiff.first)->getName() < (*FirstDiff.second)->getName()
9488 ? Comparison::Better
9489 : Comparison::Worse;
9490 }
9491 llvm_unreachable("No way to get here unless both had cpu_dispatch");
9492}
9493
9494/// Compute the type of the implicit object parameter for the given function,
9495/// if any. Returns None if there is no implicit object parameter, and a null
9496/// QualType if there is a 'matches anything' implicit object parameter.
9497static Optional<QualType> getImplicitObjectParamType(ASTContext &Context,
9498 const FunctionDecl *F) {
9499 if (!isa<CXXMethodDecl>(F) || isa<CXXConstructorDecl>(F))
9500 return llvm::None;
9501
9502 auto *M = cast<CXXMethodDecl>(F);
9503 // Static member functions' object parameters match all types.
9504 if (M->isStatic())
9505 return QualType();
9506
9507 QualType T = M->getThisObjectType();
9508 if (M->getRefQualifier() == RQ_RValue)
9509 return Context.getRValueReferenceType(T);
9510 return Context.getLValueReferenceType(T);
9511}
9512
9513static bool haveSameParameterTypes(ASTContext &Context, const FunctionDecl *F1,
9514 const FunctionDecl *F2, unsigned NumParams) {
9515 if (declaresSameEntity(F1, F2))
9516 return true;
9517
9518 auto NextParam = [&](const FunctionDecl *F, unsigned &I, bool First) {
9519 if (First) {
9520 if (Optional<QualType> T = getImplicitObjectParamType(Context, F))
9521 return *T;
9522 }
9523 assert(I < F->getNumParams());
9524 return F->getParamDecl(I++)->getType();
9525 };
9526
9527 unsigned I1 = 0, I2 = 0;
9528 for (unsigned I = 0; I != NumParams; ++I) {
9529 QualType T1 = NextParam(F1, I1, I == 0);
9530 QualType T2 = NextParam(F2, I2, I == 0);
9531 if (!T1.isNull() && !T1.isNull() && !Context.hasSameUnqualifiedType(T1, T2))
9532 return false;
9533 }
9534 return true;
9535}
9536
9537/// isBetterOverloadCandidate - Determines whether the first overload
9538/// candidate is a better candidate than the second (C++ 13.3.3p1).
9539bool clang::isBetterOverloadCandidate(
9540 Sema &S, const OverloadCandidate &Cand1, const OverloadCandidate &Cand2,
9541 SourceLocation Loc, OverloadCandidateSet::CandidateSetKind Kind) {
9542 // Define viable functions to be better candidates than non-viable
9543 // functions.
9544 if (!Cand2.Viable)
9545 return Cand1.Viable;
9546 else if (!Cand1.Viable)
9547 return false;
9548
9549 // [CUDA] A function with 'never' preference is marked not viable, therefore
9550 // is never shown up here. The worst preference shown up here is 'wrong side',
9551 // e.g. an H function called by a HD function in device compilation. This is
9552 // valid AST as long as the HD function is not emitted, e.g. it is an inline
9553 // function which is called only by an H function. A deferred diagnostic will
9554 // be triggered if it is emitted. However a wrong-sided function is still
9555 // a viable candidate here.
9556 //
9557 // If Cand1 can be emitted and Cand2 cannot be emitted in the current
9558 // context, Cand1 is better than Cand2. If Cand1 can not be emitted and Cand2
9559 // can be emitted, Cand1 is not better than Cand2. This rule should have
9560 // precedence over other rules.
9561 //
9562 // If both Cand1 and Cand2 can be emitted, or neither can be emitted, then
9563 // other rules should be used to determine which is better. This is because
9564 // host/device based overloading resolution is mostly for determining
9565 // viability of a function. If two functions are both viable, other factors
9566 // should take precedence in preference, e.g. the standard-defined preferences
9567 // like argument conversion ranks or enable_if partial-ordering. The
9568 // preference for pass-object-size parameters is probably most similar to a
9569 // type-based-overloading decision and so should take priority.
9570 //
9571 // If other rules cannot determine which is better, CUDA preference will be
9572 // used again to determine which is better.
9573 //
9574 // TODO: Currently IdentifyCUDAPreference does not return correct values
9575 // for functions called in global variable initializers due to missing
9576 // correct context about device/host. Therefore we can only enforce this
9577 // rule when there is a caller. We should enforce this rule for functions
9578 // in global variable initializers once proper context is added.
9579 //
9580 // TODO: We can only enable the hostness based overloading resolution when
9581 // -fgpu-exclude-wrong-side-overloads is on since this requires deferring
9582 // overloading resolution diagnostics.
9583 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function &&
9584 S.getLangOpts().GPUExcludeWrongSideOverloads) {
9585 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) {
9586 bool IsCallerImplicitHD = Sema::isCUDAImplicitHostDeviceFunction(Caller);
9587 bool IsCand1ImplicitHD =
9588 Sema::isCUDAImplicitHostDeviceFunction(Cand1.Function);
9589 bool IsCand2ImplicitHD =
9590 Sema::isCUDAImplicitHostDeviceFunction(Cand2.Function);
9591 auto P1 = S.IdentifyCUDAPreference(Caller, Cand1.Function);
9592 auto P2 = S.IdentifyCUDAPreference(Caller, Cand2.Function);
9593 assert(P1 != Sema::CFP_Never && P2 != Sema::CFP_Never);
9594 // The implicit HD function may be a function in a system header which
9595 // is forced by pragma. In device compilation, if we prefer HD candidates
9596 // over wrong-sided candidates, overloading resolution may change, which
9597 // may result in non-deferrable diagnostics. As a workaround, we let
9598 // implicit HD candidates take equal preference as wrong-sided candidates.
9599 // This will preserve the overloading resolution.
9600 // TODO: We still need special handling of implicit HD functions since
9601 // they may incur other diagnostics to be deferred. We should make all
9602 // host/device related diagnostics deferrable and remove special handling
9603 // of implicit HD functions.
9604 auto EmitThreshold =
9605 (S.getLangOpts().CUDAIsDevice && IsCallerImplicitHD &&
9606 (IsCand1ImplicitHD || IsCand2ImplicitHD))
9607 ? Sema::CFP_Never
9608 : Sema::CFP_WrongSide;
9609 auto Cand1Emittable = P1 > EmitThreshold;
9610 auto Cand2Emittable = P2 > EmitThreshold;
9611 if (Cand1Emittable && !Cand2Emittable)
9612 return true;
9613 if (!Cand1Emittable && Cand2Emittable)
9614 return false;
9615 }
9616 }
9617
9618 // C++ [over.match.best]p1:
9619 //
9620 // -- if F is a static member function, ICS1(F) is defined such
9621 // that ICS1(F) is neither better nor worse than ICS1(G) for
9622 // any function G, and, symmetrically, ICS1(G) is neither
9623 // better nor worse than ICS1(F).
9624 unsigned StartArg = 0;
9625 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
9626 StartArg = 1;
9627
9628 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
9629 // We don't allow incompatible pointer conversions in C++.
9630 if (!S.getLangOpts().CPlusPlus)
9631 return ICS.isStandard() &&
9632 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
9633
9634 // The only ill-formed conversion we allow in C++ is the string literal to
9635 // char* conversion, which is only considered ill-formed after C++11.
9636 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
9637 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
9638 };
9639
9640 // Define functions that don't require ill-formed conversions for a given
9641 // argument to be better candidates than functions that do.
9642 unsigned NumArgs = Cand1.Conversions.size();
9643 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
9644 bool HasBetterConversion = false;
9645 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9646 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
9647 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
9648 if (Cand1Bad != Cand2Bad) {
9649 if (Cand1Bad)
9650 return false;
9651 HasBetterConversion = true;
9652 }
9653 }
9654
9655 if (HasBetterConversion)
9656 return true;
9657
9658 // C++ [over.match.best]p1:
9659 // A viable function F1 is defined to be a better function than another
9660 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
9661 // conversion sequence than ICSi(F2), and then...
9662 bool HasWorseConversion = false;
9663 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9664 switch (CompareImplicitConversionSequences(S, Loc,
9665 Cand1.Conversions[ArgIdx],
9666 Cand2.Conversions[ArgIdx])) {
9667 case ImplicitConversionSequence::Better:
9668 // Cand1 has a better conversion sequence.
9669 HasBetterConversion = true;
9670 break;
9671
9672 case ImplicitConversionSequence::Worse:
9673 if (Cand1.Function && Cand2.Function &&
9674 Cand1.isReversed() != Cand2.isReversed() &&
9675 haveSameParameterTypes(S.Context, Cand1.Function, Cand2.Function,
9676 NumArgs)) {
9677 // Work around large-scale breakage caused by considering reversed
9678 // forms of operator== in C++20:
9679 //
9680 // When comparing a function against a reversed function with the same
9681 // parameter types, if we have a better conversion for one argument and
9682 // a worse conversion for the other, the implicit conversion sequences
9683 // are treated as being equally good.
9684 //
9685 // This prevents a comparison function from being considered ambiguous
9686 // with a reversed form that is written in the same way.
9687 //
9688 // We diagnose this as an extension from CreateOverloadedBinOp.
9689 HasWorseConversion = true;
9690 break;
9691 }
9692
9693 // Cand1 can't be better than Cand2.
9694 return false;
9695
9696 case ImplicitConversionSequence::Indistinguishable:
9697 // Do nothing.
9698 break;
9699 }
9700 }
9701
9702 // -- for some argument j, ICSj(F1) is a better conversion sequence than
9703 // ICSj(F2), or, if not that,
9704 if (HasBetterConversion && !HasWorseConversion)
9705 return true;
9706
9707 // -- the context is an initialization by user-defined conversion
9708 // (see 8.5, 13.3.1.5) and the standard conversion sequence
9709 // from the return type of F1 to the destination type (i.e.,
9710 // the type of the entity being initialized) is a better
9711 // conversion sequence than the standard conversion sequence
9712 // from the return type of F2 to the destination type.
9713 if (Kind == OverloadCandidateSet::CSK_InitByUserDefinedConversion &&
9714 Cand1.Function && Cand2.Function &&
9715 isa<CXXConversionDecl>(Cand1.Function) &&
9716 isa<CXXConversionDecl>(Cand2.Function)) {
9717 // First check whether we prefer one of the conversion functions over the
9718 // other. This only distinguishes the results in non-standard, extension
9719 // cases such as the conversion from a lambda closure type to a function
9720 // pointer or block.
9721 ImplicitConversionSequence::CompareKind Result =
9722 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
9723 if (Result == ImplicitConversionSequence::Indistinguishable)
9724 Result = CompareStandardConversionSequences(S, Loc,
9725 Cand1.FinalConversion,
9726 Cand2.FinalConversion);
9727
9728 if (Result != ImplicitConversionSequence::Indistinguishable)
9729 return Result == ImplicitConversionSequence::Better;
9730
9731 // FIXME: Compare kind of reference binding if conversion functions
9732 // convert to a reference type used in direct reference binding, per
9733 // C++14 [over.match.best]p1 section 2 bullet 3.
9734 }
9735
9736 // FIXME: Work around a defect in the C++17 guaranteed copy elision wording,
9737 // as combined with the resolution to CWG issue 243.
9738 //
9739 // When the context is initialization by constructor ([over.match.ctor] or
9740 // either phase of [over.match.list]), a constructor is preferred over
9741 // a conversion function.
9742 if (Kind == OverloadCandidateSet::CSK_InitByConstructor && NumArgs == 1 &&
9743 Cand1.Function && Cand2.Function &&
9744 isa<CXXConstructorDecl>(Cand1.Function) !=
9745 isa<CXXConstructorDecl>(Cand2.Function))
9746 return isa<CXXConstructorDecl>(Cand1.Function);
9747
9748 // -- F1 is a non-template function and F2 is a function template
9749 // specialization, or, if not that,
9750 bool Cand1IsSpecialization = Cand1.Function &&
9751 Cand1.Function->getPrimaryTemplate();
9752 bool Cand2IsSpecialization = Cand2.Function &&
9753 Cand2.Function->getPrimaryTemplate();
9754 if (Cand1IsSpecialization != Cand2IsSpecialization)
9755 return Cand2IsSpecialization;
9756
9757 // -- F1 and F2 are function template specializations, and the function
9758 // template for F1 is more specialized than the template for F2
9759 // according to the partial ordering rules described in 14.5.5.2, or,
9760 // if not that,
9761 if (Cand1IsSpecialization && Cand2IsSpecialization) {
9762 if (FunctionTemplateDecl *BetterTemplate = S.getMoreSpecializedTemplate(
9763 Cand1.Function->getPrimaryTemplate(),
9764 Cand2.Function->getPrimaryTemplate(), Loc,
9765 isa<CXXConversionDecl>(Cand1.Function) ? TPOC_Conversion
9766 : TPOC_Call,
9767 Cand1.ExplicitCallArguments, Cand2.ExplicitCallArguments,
9768 Cand1.isReversed() ^ Cand2.isReversed()))
9769 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
9770 }
9771
9772 // -— F1 and F2 are non-template functions with the same
9773 // parameter-type-lists, and F1 is more constrained than F2 [...],
9774 if (Cand1.Function && Cand2.Function && !Cand1IsSpecialization &&
9775 !Cand2IsSpecialization && Cand1.Function->hasPrototype() &&
9776 Cand2.Function->hasPrototype()) {
9777 auto *PT1 = cast<FunctionProtoType>(Cand1.Function->getFunctionType());
9778 auto *PT2 = cast<FunctionProtoType>(Cand2.Function->getFunctionType());
9779 if (PT1->getNumParams() == PT2->getNumParams() &&
9780 PT1->isVariadic() == PT2->isVariadic() &&
9781 S.FunctionParamTypesAreEqual(PT1, PT2)) {
9782 Expr *RC1 = Cand1.Function->getTrailingRequiresClause();
9783 Expr *RC2 = Cand2.Function->getTrailingRequiresClause();
9784 if (RC1 && RC2) {
9785 bool AtLeastAsConstrained1, AtLeastAsConstrained2;
9786 if (S.IsAtLeastAsConstrained(Cand1.Function, {RC1}, Cand2.Function,
9787 {RC2}, AtLeastAsConstrained1) ||
9788 S.IsAtLeastAsConstrained(Cand2.Function, {RC2}, Cand1.Function,
9789 {RC1}, AtLeastAsConstrained2))
9790 return false;
9791 if (AtLeastAsConstrained1 != AtLeastAsConstrained2)
9792 return AtLeastAsConstrained1;
9793 } else if (RC1 || RC2) {
9794 return RC1 != nullptr;
9795 }
9796 }
9797 }
9798
9799 // -- F1 is a constructor for a class D, F2 is a constructor for a base
9800 // class B of D, and for all arguments the corresponding parameters of
9801 // F1 and F2 have the same type.
9802 // FIXME: Implement the "all parameters have the same type" check.
9803 bool Cand1IsInherited =
9804 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
9805 bool Cand2IsInherited =
9806 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
9807 if (Cand1IsInherited != Cand2IsInherited)
9808 return Cand2IsInherited;
9809 else if (Cand1IsInherited) {
9810 assert(Cand2IsInherited);
9811 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
9812 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
9813 if (Cand1Class->isDerivedFrom(Cand2Class))
9814 return true;
9815 if (Cand2Class->isDerivedFrom(Cand1Class))
9816 return false;
9817 // Inherited from sibling base classes: still ambiguous.
9818 }
9819
9820 // -- F2 is a rewritten candidate (12.4.1.2) and F1 is not
9821 // -- F1 and F2 are rewritten candidates, and F2 is a synthesized candidate
9822 // with reversed order of parameters and F1 is not
9823 //
9824 // We rank reversed + different operator as worse than just reversed, but
9825 // that comparison can never happen, because we only consider reversing for
9826 // the maximally-rewritten operator (== or <=>).
9827 if (Cand1.RewriteKind != Cand2.RewriteKind)
9828 return Cand1.RewriteKind < Cand2.RewriteKind;
9829
9830 // Check C++17 tie-breakers for deduction guides.
9831 {
9832 auto *Guide1 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand1.Function);
9833 auto *Guide2 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand2.Function);
9834 if (Guide1 && Guide2) {
9835 // -- F1 is generated from a deduction-guide and F2 is not
9836 if (Guide1->isImplicit() != Guide2->isImplicit())
9837 return Guide2->isImplicit();
9838
9839 // -- F1 is the copy deduction candidate(16.3.1.8) and F2 is not
9840 if (Guide1->isCopyDeductionCandidate())
9841 return true;
9842 }
9843 }
9844
9845 // Check for enable_if value-based overload resolution.
9846 if (Cand1.Function && Cand2.Function) {
9847 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
9848 if (Cmp != Comparison::Equal)
9849 return Cmp == Comparison::Better;
9850 }
9851
9852 bool HasPS1 = Cand1.Function != nullptr &&
9853 functionHasPassObjectSizeParams(Cand1.Function);
9854 bool HasPS2 = Cand2.Function != nullptr &&
9855 functionHasPassObjectSizeParams(Cand2.Function);
9856 if (HasPS1 != HasPS2 && HasPS1)
9857 return true;
9858
9859 auto MV = isBetterMultiversionCandidate(Cand1, Cand2);
9860 if (MV == Comparison::Better)
9861 return true;
9862 if (MV == Comparison::Worse)
9863 return false;
9864
9865 // If other rules cannot determine which is better, CUDA preference is used
9866 // to determine which is better.
9867 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
9868 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9869 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
9870 S.IdentifyCUDAPreference(Caller, Cand2.Function);
9871 }
9872
9873 return false;
9874}
9875
9876/// Determine whether two declarations are "equivalent" for the purposes of
9877/// name lookup and overload resolution. This applies when the same internal/no
9878/// linkage entity is defined by two modules (probably by textually including
9879/// the same header). In such a case, we don't consider the declarations to
9880/// declare the same entity, but we also don't want lookups with both
9881/// declarations visible to be ambiguous in some cases (this happens when using
9882/// a modularized libstdc++).
9883bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
9884 const NamedDecl *B) {
9885 auto *VA = dyn_cast_or_null<ValueDecl>(A);
9886 auto *VB = dyn_cast_or_null<ValueDecl>(B);
9887 if (!VA || !VB)
9888 return false;
9889
9890 // The declarations must be declaring the same name as an internal linkage
9891 // entity in different modules.
9892 if (!VA->getDeclContext()->getRedeclContext()->Equals(
9893 VB->getDeclContext()->getRedeclContext()) ||
9894 getOwningModule(VA) == getOwningModule(VB) ||
9895 VA->isExternallyVisible() || VB->isExternallyVisible())
9896 return false;
9897
9898 // Check that the declarations appear to be equivalent.
9899 //
9900 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
9901 // For constants and functions, we should check the initializer or body is
9902 // the same. For non-constant variables, we shouldn't allow it at all.
9903 if (Context.hasSameType(VA->getType(), VB->getType()))
9904 return true;
9905
9906 // Enum constants within unnamed enumerations will have different types, but
9907 // may still be similar enough to be interchangeable for our purposes.
9908 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
9909 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
9910 // Only handle anonymous enums. If the enumerations were named and
9911 // equivalent, they would have been merged to the same type.
9912 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
9913 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
9914 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
9915 !Context.hasSameType(EnumA->getIntegerType(),
9916 EnumB->getIntegerType()))
9917 return false;
9918 // Allow this only if the value is the same for both enumerators.
9919 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
9920 }
9921 }
9922
9923 // Nothing else is sufficiently similar.
9924 return false;
9925}
9926
9927void Sema::diagnoseEquivalentInternalLinkageDeclarations(
9928 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
9929 assert(D && "Unknown declaration");
9930 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
9931
9932 Module *M = getOwningModule(D);
9933 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
9934 << !M << (M ? M->getFullModuleName() : "");
9935
9936 for (auto *E : Equiv) {
9937 Module *M = getOwningModule(E);
9938 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
9939 << !M << (M ? M->getFullModuleName() : "");
9940 }
9941}
9942
9943/// Computes the best viable function (C++ 13.3.3)
9944/// within an overload candidate set.
9945///
9946/// \param Loc The location of the function name (or operator symbol) for
9947/// which overload resolution occurs.
9948///
9949/// \param Best If overload resolution was successful or found a deleted
9950/// function, \p Best points to the candidate function found.
9951///
9952/// \returns The result of overload resolution.
9953OverloadingResult
9954OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
9955 iterator &Best) {
9956 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
9957 std::transform(begin(), end(), std::back_inserter(Candidates),
9958 [](OverloadCandidate &Cand) { return &Cand; });
9959
9960 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
9961 // are accepted by both clang and NVCC. However, during a particular
9962 // compilation mode only one call variant is viable. We need to
9963 // exclude non-viable overload candidates from consideration based
9964 // only on their host/device attributes. Specifically, if one
9965 // candidate call is WrongSide and the other is SameSide, we ignore
9966 // the WrongSide candidate.
9967 // We only need to remove wrong-sided candidates here if
9968 // -fgpu-exclude-wrong-side-overloads is off. When
9969 // -fgpu-exclude-wrong-side-overloads is on, all candidates are compared
9970 // uniformly in isBetterOverloadCandidate.
9971 if (S.getLangOpts().CUDA && !S.getLangOpts().GPUExcludeWrongSideOverloads) {
9972 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9973 bool ContainsSameSideCandidate =
9974 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
9975 // Check viable function only.
9976 return Cand->Viable && Cand->Function &&
9977 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9978 Sema::CFP_SameSide;
9979 });
9980 if (ContainsSameSideCandidate) {
9981 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
9982 // Check viable function only to avoid unnecessary data copying/moving.
9983 return Cand->Viable && Cand->Function &&
9984 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9985 Sema::CFP_WrongSide;
9986 };
9987 llvm::erase_if(Candidates, IsWrongSideCandidate);
9988 }
9989 }
9990
9991 // Find the best viable function.
9992 Best = end();
9993 for (auto *Cand : Candidates) {
9994 Cand->Best = false;
9995 if (Cand->Viable)
9996 if (Best == end() ||
9997 isBetterOverloadCandidate(S, *Cand, *Best, Loc, Kind))
9998 Best = Cand;
9999 }
10000
10001 // If we didn't find any viable functions, abort.
10002 if (Best == end())
10003 return OR_No_Viable_Function;
10004
10005 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
10006
10007 llvm::SmallVector<OverloadCandidate*, 4> PendingBest;
10008 PendingBest.push_back(&*Best);
10009 Best->Best = true;
10010
10011 // Make sure that this function is better than every other viable
10012 // function. If not, we have an ambiguity.
10013 while (!PendingBest.empty()) {
10014 auto *Curr = PendingBest.pop_back_val();
10015 for (auto *Cand : Candidates) {
10016 if (Cand->Viable && !Cand->Best &&
10017 !isBetterOverloadCandidate(S, *Curr, *Cand, Loc, Kind)) {
10018 PendingBest.push_back(Cand);
10019 Cand->Best = true;
10020
10021 if (S.isEquivalentInternalLinkageDeclaration(Cand->Function,
10022 Curr->Function))
10023 EquivalentCands.push_back(Cand->Function);
10024 else
10025 Best = end();
10026 }
10027 }
10028 }
10029
10030 // If we found more than one best candidate, this is ambiguous.
10031 if (Best == end())
10032 return OR_Ambiguous;
10033
10034 // Best is the best viable function.
10035 if (Best->Function && Best->Function->isDeleted())
10036 return OR_Deleted;
10037
10038 if (!EquivalentCands.empty())
10039 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
10040 EquivalentCands);
10041
10042 return OR_Success;
10043}
10044
10045namespace {
10046
10047enum OverloadCandidateKind {
10048 oc_function,
10049 oc_method,
10050 oc_reversed_binary_operator,
10051 oc_constructor,
10052 oc_implicit_default_constructor,
10053 oc_implicit_copy_constructor,
10054 oc_implicit_move_constructor,
10055 oc_implicit_copy_assignment,
10056 oc_implicit_move_assignment,
10057 oc_implicit_equality_comparison,
10058 oc_inherited_constructor
10059};
10060
10061enum OverloadCandidateSelect {
10062 ocs_non_template,
10063 ocs_template,
10064 ocs_described_template,
10065};
10066
10067static std::pair<OverloadCandidateKind, OverloadCandidateSelect>
10068ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
10069 OverloadCandidateRewriteKind CRK,
10070 std::string &Description) {
10071
10072 bool isTemplate = Fn->isTemplateDecl() || Found->isTemplateDecl();
10073 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
10074 isTemplate = true;
10075 Description = S.getTemplateArgumentBindingsText(
10076 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
10077 }
10078
10079 OverloadCandidateSelect Select = [&]() {
10080 if (!Description.empty())
10081 return ocs_described_template;
10082 return isTemplate ? ocs_template : ocs_non_template;
10083 }();
10084
10085 OverloadCandidateKind Kind = [&]() {
10086 if (Fn->isImplicit() && Fn->getOverloadedOperator() == OO_EqualEqual)
10087 return oc_implicit_equality_comparison;
10088
10089 if (CRK & CRK_Reversed)
10090 return oc_reversed_binary_operator;
10091
10092 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
10093 if (!Ctor->isImplicit()) {
10094 if (isa<ConstructorUsingShadowDecl>(Found))
10095 return oc_inherited_constructor;
10096 else
10097 return oc_constructor;
10098 }
10099
10100 if (Ctor->isDefaultConstructor())
10101 return oc_implicit_default_constructor;
10102
10103 if (Ctor->isMoveConstructor())
10104 return oc_implicit_move_constructor;
10105
10106 assert(Ctor->isCopyConstructor() &&
10107 "unexpected sort of implicit constructor");
10108 return oc_implicit_copy_constructor;
10109 }
10110
10111 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
10112 // This actually gets spelled 'candidate function' for now, but
10113 // it doesn't hurt to split it out.
10114 if (!Meth->isImplicit())
10115 return oc_method;
10116
10117 if (Meth->isMoveAssignmentOperator())
10118 return oc_implicit_move_assignment;
10119
10120 if (Meth->isCopyAssignmentOperator())
10121 return oc_implicit_copy_assignment;
10122
10123 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
10124 return oc_method;
10125 }
10126
10127 return oc_function;
10128 }();
10129
10130 return std::make_pair(Kind, Select);
10131}
10132
10133void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
10134 // FIXME: It'd be nice to only emit a note once per using-decl per overload
10135 // set.
10136 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
10137 S.Diag(FoundDecl->getLocation(),
10138 diag::note_ovl_candidate_inherited_constructor)
10139 << Shadow->getNominatedBaseClass();
10140}
10141
10142} // end anonymous namespace
10143
10144static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
10145 const FunctionDecl *FD) {
10146 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
10147 bool AlwaysTrue;
10148 if (EnableIf->getCond()->isValueDependent() ||
10149 !EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
10150 return false;
10151 if (!AlwaysTrue)
10152 return false;
10153 }
10154 return true;
10155}
10156
10157/// Returns true if we can take the address of the function.
10158///
10159/// \param Complain - If true, we'll emit a diagnostic
10160/// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
10161/// we in overload resolution?
10162/// \param Loc - The location of the statement we're complaining about. Ignored
10163/// if we're not complaining, or if we're in overload resolution.
10164static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
10165 bool Complain,
10166 bool InOverloadResolution,
10167 SourceLocation Loc) {
10168 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
10169 if (Complain) {
10170 if (InOverloadResolution)
10171 S.Diag(FD->getBeginLoc(),
10172 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
10173 else
10174 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
10175 }
10176 return false;
10177 }
10178
10179 if (FD->getTrailingRequiresClause()) {
10180 ConstraintSatisfaction Satisfaction;
10181 if (S.CheckFunctionConstraints(FD, Satisfaction, Loc))
10182 return false;
10183 if (!Satisfaction.IsSatisfied) {
10184 if (Complain) {
10185 if (InOverloadResolution)
10186 S.Diag(FD->getBeginLoc(),
10187 diag::note_ovl_candidate_unsatisfied_constraints);
10188 else
10189 S.Diag(Loc, diag::err_addrof_function_constraints_not_satisfied)
10190 << FD;
10191 S.DiagnoseUnsatisfiedConstraint(Satisfaction);
10192 }
10193 return false;
10194 }
10195 }
10196
10197 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
10198 return P->hasAttr<PassObjectSizeAttr>();
10199 });
10200 if (I == FD->param_end())
10201 return true;
10202
10203 if (Complain) {
10204 // Add one to ParamNo because it's user-facing
10205 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
10206 if (InOverloadResolution)
10207 S.Diag(FD->getLocation(),
10208 diag::note_ovl_candidate_has_pass_object_size_params)
10209 << ParamNo;
10210 else
10211 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
10212 << FD << ParamNo;
10213 }
10214 return false;
10215}
10216
10217static bool checkAddressOfCandidateIsAvailable(Sema &S,
10218 const FunctionDecl *FD) {
10219 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
10220 /*InOverloadResolution=*/true,
10221 /*Loc=*/SourceLocation());
10222}
10223
10224bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
10225 bool Complain,
10226 SourceLocation Loc) {
10227 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
10228 /*InOverloadResolution=*/false,
10229 Loc);
10230}
10231
10232// Don't print candidates other than the one that matches the calling
10233// convention of the call operator, since that is guaranteed to exist.
10234static bool shouldSkipNotingLambdaConversionDecl(FunctionDecl *Fn) {
10235 const auto *ConvD = dyn_cast<CXXConversionDecl>(Fn);
10236
10237 if (!ConvD)
10238 return false;
10239 const auto *RD = cast<CXXRecordDecl>(Fn->getParent());
10240 if (!RD->isLambda())
10241 return false;
10242
10243 CXXMethodDecl *CallOp = RD->getLambdaCallOperator();
10244 CallingConv CallOpCC =
10245 CallOp->getType()->getAs<FunctionType>()->getCallConv();
10246 QualType ConvRTy = ConvD->getType()->getAs<FunctionType>()->getReturnType();
10247 CallingConv ConvToCC =
10248 ConvRTy->getPointeeType()->getAs<FunctionType>()->getCallConv();
10249
10250 return ConvToCC != CallOpCC;
10251}
10252
10253// Notes the location of an overload candidate.
10254void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
10255 OverloadCandidateRewriteKind RewriteKind,
10256 QualType DestType, bool TakingAddress) {
10257 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
10258 return;
10259 if (Fn->isMultiVersion() && Fn->hasAttr<TargetAttr>() &&
10260 !Fn->getAttr<TargetAttr>()->isDefaultVersion())
10261 return;
10262 if (shouldSkipNotingLambdaConversionDecl(Fn))
10263 return;
10264
10265 std::string FnDesc;
10266 std::pair<OverloadCandidateKind, OverloadCandidateSelect> KSPair =
10267 ClassifyOverloadCandidate(*this, Found, Fn, RewriteKind, FnDesc);
10268 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
10269 << (unsigned)KSPair.first << (unsigned)KSPair.second
10270 << Fn << FnDesc;
10271
10272 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
10273 Diag(Fn->getLocation(), PD);
10274 MaybeEmitInheritedConstructorNote(*this, Found);
10275}
10276
10277static void
10278MaybeDiagnoseAmbiguousConstraints(Sema &S, ArrayRef<OverloadCandidate> Cands) {
10279 // Perhaps the ambiguity was caused by two atomic constraints that are
10280 // 'identical' but not equivalent:
10281 //
10282 // void foo() requires (sizeof(T) > 4) { } // #1
10283 // void foo() requires (sizeof(T) > 4) && T::value { } // #2
10284 //
10285 // The 'sizeof(T) > 4' constraints are seemingly equivalent and should cause
10286 // #2 to subsume #1, but these constraint are not considered equivalent
10287 // according to the subsumption rules because they are not the same
10288 // source-level construct. This behavior is quite confusing and we should try
10289 // to help the user figure out what happened.
10290
10291 SmallVector<const Expr *, 3> FirstAC, SecondAC;
10292 FunctionDecl *FirstCand = nullptr, *SecondCand = nullptr;
10293 for (auto I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10294 if (!I->Function)
10295 continue;
10296 SmallVector<const Expr *, 3> AC;
10297 if (auto *Template = I->Function->getPrimaryTemplate())
10298 Template->getAssociatedConstraints(AC);
10299 else
10300 I->Function->getAssociatedConstraints(AC);
10301 if (AC.empty())
10302 continue;
10303 if (FirstCand == nullptr) {
10304 FirstCand = I->Function;
10305 FirstAC = AC;
10306 } else if (SecondCand == nullptr) {
10307 SecondCand = I->Function;
10308 SecondAC = AC;
10309 } else {
10310 // We have more than one pair of constrained functions - this check is
10311 // expensive and we'd rather not try to diagnose it.
10312 return;
10313 }
10314 }
10315 if (!SecondCand)
10316 return;
10317 // The diagnostic can only happen if there are associated constraints on
10318 // both sides (there needs to be some identical atomic constraint).
10319 if (S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(FirstCand, FirstAC,
10320 SecondCand, SecondAC))
10321 // Just show the user one diagnostic, they'll probably figure it out
10322 // from here.
10323 return;
10324}
10325
10326// Notes the location of all overload candidates designated through
10327// OverloadedExpr
10328void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
10329 bool TakingAddress) {
10330 assert(OverloadedExpr->getType() == Context.OverloadTy);
10331
10332 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
10333 OverloadExpr *OvlExpr = Ovl.Expression;
10334
10335 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10336 IEnd = OvlExpr->decls_end();
10337 I != IEnd; ++I) {
10338 if (FunctionTemplateDecl *FunTmpl =
10339 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
10340 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), CRK_None, DestType,
10341 TakingAddress);
10342 } else if (FunctionDecl *Fun
10343 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
10344 NoteOverloadCandidate(*I, Fun, CRK_None, DestType, TakingAddress);
10345 }
10346 }
10347}
10348
10349/// Diagnoses an ambiguous conversion. The partial diagnostic is the
10350/// "lead" diagnostic; it will be given two arguments, the source and
10351/// target types of the conversion.
10352void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
10353 Sema &S,
10354 SourceLocation CaretLoc,
10355 const PartialDiagnostic &PDiag) const {
10356 S.Diag(CaretLoc, PDiag)
10357 << Ambiguous.getFromType() << Ambiguous.getToType();
10358 // FIXME: The note limiting machinery is borrowed from
10359 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
10360 // refactoring here.
10361 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10362 unsigned CandsShown = 0;
10363 AmbiguousConversionSequence::const_iterator I, E;
10364 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
10365 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10366 break;
10367 ++CandsShown;
10368 S.NoteOverloadCandidate(I->first, I->second);
10369 }
10370 if (I != E)
10371 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
10372}
10373
10374static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
10375 unsigned I, bool TakingCandidateAddress) {
10376 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
10377 assert(Conv.isBad());
10378 assert(Cand->Function && "for now, candidate must be a function");
10379 FunctionDecl *Fn = Cand->Function;
10380
10381 // There's a conversion slot for the object argument if this is a
10382 // non-constructor method. Note that 'I' corresponds the
10383 // conversion-slot index.
10384 bool isObjectArgument = false;
10385 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
10386 if (I == 0)
10387 isObjectArgument = true;
10388 else
10389 I--;
10390 }
10391
10392 std::string FnDesc;
10393 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10394 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, Cand->getRewriteKind(),
10395 FnDesc);
10396
10397 Expr *FromExpr = Conv.Bad.FromExpr;
10398 QualType FromTy = Conv.Bad.getFromType();
10399 QualType ToTy = Conv.Bad.getToType();
10400
10401 if (FromTy == S.Context.OverloadTy) {
10402 assert(FromExpr && "overload set argument came from implicit argument?");
10403 Expr *E = FromExpr->IgnoreParens();
10404 if (isa<UnaryOperator>(E))
10405 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
10406 DeclarationName Name = cast<OverloadExpr>(E)->getName();
10407
10408 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
10409 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10410 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << ToTy
10411 << Name << I + 1;
10412 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10413 return;
10414 }
10415
10416 // Do some hand-waving analysis to see if the non-viability is due
10417 // to a qualifier mismatch.
10418 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
10419 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
10420 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
10421 CToTy = RT->getPointeeType();
10422 else {
10423 // TODO: detect and diagnose the full richness of const mismatches.
10424 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
10425 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
10426 CFromTy = FromPT->getPointeeType();
10427 CToTy = ToPT->getPointeeType();
10428 }
10429 }
10430
10431 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
10432 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
10433 Qualifiers FromQs = CFromTy.getQualifiers();
10434 Qualifiers ToQs = CToTy.getQualifiers();
10435
10436 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
10437 if (isObjectArgument)
10438 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace_this)
10439 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10440 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10441 << FromQs.getAddressSpace() << ToQs.getAddressSpace();
10442 else
10443 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
10444 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10445 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10446 << FromQs.getAddressSpace() << ToQs.getAddressSpace()
10447 << ToTy->isReferenceType() << I + 1;
10448 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10449 return;
10450 }
10451
10452 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
10453 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
10454 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10455 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10456 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
10457 << (unsigned)isObjectArgument << I + 1;
10458 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10459 return;
10460 }
10461
10462 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
10463 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
10464 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10465 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10466 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
10467 << (unsigned)isObjectArgument << I + 1;
10468 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10469 return;
10470 }
10471
10472 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
10473 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
10474 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10475 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10476 << FromQs.hasUnaligned() << I + 1;
10477 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10478 return;
10479 }
10480
10481 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
10482 assert(CVR && "expected qualifiers mismatch");
10483
10484 if (isObjectArgument) {
10485 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
10486 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10487 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10488 << (CVR - 1);
10489 } else {
10490 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
10491 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10492 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10493 << (CVR - 1) << I + 1;
10494 }
10495 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10496 return;
10497 }
10498
10499 if (Conv.Bad.Kind == BadConversionSequence::lvalue_ref_to_rvalue ||
10500 Conv.Bad.Kind == BadConversionSequence::rvalue_ref_to_lvalue) {
10501 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_value_category)
10502 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10503 << (unsigned)isObjectArgument << I + 1
10504 << (Conv.Bad.Kind == BadConversionSequence::rvalue_ref_to_lvalue)
10505 << (FromExpr ? FromExpr->getSourceRange() : SourceRange());
10506 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10507 return;
10508 }
10509
10510 // Special diagnostic for failure to convert an initializer list, since
10511 // telling the user that it has type void is not useful.
10512 if (FromExpr && isa<InitListExpr>(FromExpr)) {
10513 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
10514 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10515 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10516 << ToTy << (unsigned)isObjectArgument << I + 1;
10517 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10518 return;
10519 }
10520
10521 // Diagnose references or pointers to incomplete types differently,
10522 // since it's far from impossible that the incompleteness triggered
10523 // the failure.
10524 QualType TempFromTy = FromTy.getNonReferenceType();
10525 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
10526 TempFromTy = PTy->getPointeeType();
10527 if (TempFromTy->isIncompleteType()) {
10528 // Emit the generic diagnostic and, optionally, add the hints to it.
10529 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
10530 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10531 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10532 << ToTy << (unsigned)isObjectArgument << I + 1
10533 << (unsigned)(Cand->Fix.Kind);
10534
10535 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10536 return;
10537 }
10538
10539 // Diagnose base -> derived pointer conversions.
10540 unsigned BaseToDerivedConversion = 0;
10541 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
10542 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
10543 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
10544 FromPtrTy->getPointeeType()) &&
10545 !FromPtrTy->getPointeeType()->isIncompleteType() &&
10546 !ToPtrTy->getPointeeType()->isIncompleteType() &&
10547 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
10548 FromPtrTy->getPointeeType()))
10549 BaseToDerivedConversion = 1;
10550 }
10551 } else if (const ObjCObjectPointerType *FromPtrTy
10552 = FromTy->getAs<ObjCObjectPointerType>()) {
10553 if (const ObjCObjectPointerType *ToPtrTy
10554 = ToTy->getAs<ObjCObjectPointerType>())
10555 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
10556 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
10557 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
10558 FromPtrTy->getPointeeType()) &&
10559 FromIface->isSuperClassOf(ToIface))
10560 BaseToDerivedConversion = 2;
10561 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
10562 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
10563 !FromTy->isIncompleteType() &&
10564 !ToRefTy->getPointeeType()->isIncompleteType() &&
10565 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
10566 BaseToDerivedConversion = 3;
10567 }
10568 }
10569
10570 if (BaseToDerivedConversion) {
10571 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_base_to_derived_conv)
10572 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10573 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10574 << (BaseToDerivedConversion - 1) << FromTy << ToTy << I + 1;
10575 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10576 return;
10577 }
10578
10579 if (isa<ObjCObjectPointerType>(CFromTy) &&
10580 isa<PointerType>(CToTy)) {
10581 Qualifiers FromQs = CFromTy.getQualifiers();
10582 Qualifiers ToQs = CToTy.getQualifiers();
10583 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
10584 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
10585 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10586 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10587 << FromTy << ToTy << (unsigned)isObjectArgument << I + 1;
10588 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10589 return;
10590 }
10591 }
10592
10593 if (TakingCandidateAddress &&
10594 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
10595 return;
10596
10597 // Emit the generic diagnostic and, optionally, add the hints to it.
10598 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
10599 FDiag << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10600 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10601 << ToTy << (unsigned)isObjectArgument << I + 1
10602 << (unsigned)(Cand->Fix.Kind);
10603
10604 // If we can fix the conversion, suggest the FixIts.
10605 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
10606 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
10607 FDiag << *HI;
10608 S.Diag(Fn->getLocation(), FDiag);
10609
10610 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10611}
10612
10613/// Additional arity mismatch diagnosis specific to a function overload
10614/// candidates. This is not covered by the more general DiagnoseArityMismatch()
10615/// over a candidate in any candidate set.
10616static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
10617 unsigned NumArgs) {
10618 FunctionDecl *Fn = Cand->Function;
10619 unsigned MinParams = Fn->getMinRequiredArguments();
10620
10621 // With invalid overloaded operators, it's possible that we think we
10622 // have an arity mismatch when in fact it looks like we have the
10623 // right number of arguments, because only overloaded operators have
10624 // the weird behavior of overloading member and non-member functions.
10625 // Just don't report anything.
10626 if (Fn->isInvalidDecl() &&
10627 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
10628 return true;
10629
10630 if (NumArgs < MinParams) {
10631 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
10632 (Cand->FailureKind == ovl_fail_bad_deduction &&
10633 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
10634 } else {
10635 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
10636 (Cand->FailureKind == ovl_fail_bad_deduction &&
10637 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
10638 }
10639
10640 return false;
10641}
10642
10643/// General arity mismatch diagnosis over a candidate in a candidate set.
10644static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
10645 unsigned NumFormalArgs) {
10646 assert(isa<FunctionDecl>(D) &&
10647 "The templated declaration should at least be a function"
10648 " when diagnosing bad template argument deduction due to too many"
10649 " or too few arguments");
10650
10651 FunctionDecl *Fn = cast<FunctionDecl>(D);
10652
10653 // TODO: treat calls to a missing default constructor as a special case
10654 const auto *FnTy = Fn->getType()->castAs<FunctionProtoType>();
10655 unsigned MinParams = Fn->getMinRequiredArguments();
10656
10657 // at least / at most / exactly
10658 unsigned mode, modeCount;
10659 if (NumFormalArgs < MinParams) {
10660 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
10661 FnTy->isTemplateVariadic())
10662 mode = 0; // "at least"
10663 else
10664 mode = 2; // "exactly"
10665 modeCount = MinParams;
10666 } else {
10667 if (MinParams != FnTy->getNumParams())
10668 mode = 1; // "at most"
10669 else
10670 mode = 2; // "exactly"
10671 modeCount = FnTy->getNumParams();
10672 }
10673
10674 std::string Description;
10675 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10676 ClassifyOverloadCandidate(S, Found, Fn, CRK_None, Description);
10677
10678 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
10679 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
10680 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10681 << Description << mode << Fn->getParamDecl(0) << NumFormalArgs;
10682 else
10683 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
10684 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10685 << Description << mode << modeCount << NumFormalArgs;
10686
10687 MaybeEmitInheritedConstructorNote(S, Found);
10688}
10689
10690/// Arity mismatch diagnosis specific to a function overload candidate.
10691static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
10692 unsigned NumFormalArgs) {
10693 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
10694 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
10695}
10696
10697static TemplateDecl *getDescribedTemplate(Decl *Templated) {
10698 if (TemplateDecl *TD = Templated->getDescribedTemplate())
10699 return TD;
10700 llvm_unreachable("Unsupported: Getting the described template declaration"
10701 " for bad deduction diagnosis");
10702}
10703
10704/// Diagnose a failed template-argument deduction.
10705static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
10706 DeductionFailureInfo &DeductionFailure,
10707 unsigned NumArgs,
10708 bool TakingCandidateAddress) {
10709 TemplateParameter Param = DeductionFailure.getTemplateParameter();
10710 NamedDecl *ParamD;
10711 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
10712 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
10713 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
10714 switch (DeductionFailure.Result) {
10715 case Sema::TDK_Success:
10716 llvm_unreachable("TDK_success while diagnosing bad deduction");
10717
10718 case Sema::TDK_Incomplete: {
10719 assert(ParamD && "no parameter found for incomplete deduction result");
10720 S.Diag(Templated->getLocation(),
10721 diag::note_ovl_candidate_incomplete_deduction)
10722 << ParamD->getDeclName();
10723 MaybeEmitInheritedConstructorNote(S, Found);
10724 return;
10725 }
10726
10727 case Sema::TDK_IncompletePack: {
10728 assert(ParamD && "no parameter found for incomplete deduction result");
10729 S.Diag(Templated->getLocation(),
10730 diag::note_ovl_candidate_incomplete_deduction_pack)
10731 << ParamD->getDeclName()
10732 << (DeductionFailure.getFirstArg()->pack_size() + 1)
10733 << *DeductionFailure.getFirstArg();
10734 MaybeEmitInheritedConstructorNote(S, Found);
10735 return;
10736 }
10737
10738 case Sema::TDK_Underqualified: {
10739 assert(ParamD && "no parameter found for bad qualifiers deduction result");
10740 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
10741
10742 QualType Param = DeductionFailure.getFirstArg()->getAsType();
10743
10744 // Param will have been canonicalized, but it should just be a
10745 // qualified version of ParamD, so move the qualifiers to that.
10746 QualifierCollector Qs;
10747 Qs.strip(Param);
10748 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
10749 assert(S.Context.hasSameType(Param, NonCanonParam));
10750
10751 // Arg has also been canonicalized, but there's nothing we can do
10752 // about that. It also doesn't matter as much, because it won't
10753 // have any template parameters in it (because deduction isn't
10754 // done on dependent types).
10755 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
10756
10757 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
10758 << ParamD->getDeclName() << Arg << NonCanonParam;
10759 MaybeEmitInheritedConstructorNote(S, Found);
10760 return;
10761 }
10762
10763 case Sema::TDK_Inconsistent: {
10764 assert(ParamD && "no parameter found for inconsistent deduction result");
10765 int which = 0;
10766 if (isa<TemplateTypeParmDecl>(ParamD))
10767 which = 0;
10768 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
10769 // Deduction might have failed because we deduced arguments of two
10770 // different types for a non-type template parameter.
10771 // FIXME: Use a different TDK value for this.
10772 QualType T1 =
10773 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
10774 QualType T2 =
10775 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
10776 if (!T1.isNull() && !T2.isNull() && !S.Context.hasSameType(T1, T2)) {
10777 S.Diag(Templated->getLocation(),
10778 diag::note_ovl_candidate_inconsistent_deduction_types)
10779 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
10780 << *DeductionFailure.getSecondArg() << T2;
10781 MaybeEmitInheritedConstructorNote(S, Found);
10782 return;
10783 }
10784
10785 which = 1;
10786 } else {
10787 which = 2;
10788 }
10789
10790 // Tweak the diagnostic if the problem is that we deduced packs of
10791 // different arities. We'll print the actual packs anyway in case that
10792 // includes additional useful information.
10793 if (DeductionFailure.getFirstArg()->getKind() == TemplateArgument::Pack &&
10794 DeductionFailure.getSecondArg()->getKind() == TemplateArgument::Pack &&
10795 DeductionFailure.getFirstArg()->pack_size() !=
10796 DeductionFailure.getSecondArg()->pack_size()) {
10797 which = 3;
10798 }
10799
10800 S.Diag(Templated->getLocation(),
10801 diag::note_ovl_candidate_inconsistent_deduction)
10802 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
10803 << *DeductionFailure.getSecondArg();
10804 MaybeEmitInheritedConstructorNote(S, Found);
10805 return;
10806 }
10807
10808 case Sema::TDK_InvalidExplicitArguments:
10809 assert(ParamD && "no parameter found for invalid explicit arguments");
10810 if (ParamD->getDeclName())
10811 S.Diag(Templated->getLocation(),
10812 diag::note_ovl_candidate_explicit_arg_mismatch_named)
10813 << ParamD->getDeclName();
10814 else {
10815 int index = 0;
10816 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
10817 index = TTP->getIndex();
10818 else if (NonTypeTemplateParmDecl *NTTP
10819 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
10820 index = NTTP->getIndex();
10821 else
10822 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
10823 S.Diag(Templated->getLocation(),
10824 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
10825 << (index + 1);
10826 }
10827 MaybeEmitInheritedConstructorNote(S, Found);
10828 return;
10829
10830 case Sema::TDK_ConstraintsNotSatisfied: {
10831 // Format the template argument list into the argument string.
10832 SmallString<128> TemplateArgString;
10833 TemplateArgumentList *Args = DeductionFailure.getTemplateArgumentList();
10834 TemplateArgString = " ";
10835 TemplateArgString += S.getTemplateArgumentBindingsText(
10836 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10837 if (TemplateArgString.size() == 1)
10838 TemplateArgString.clear();
10839 S.Diag(Templated->getLocation(),
10840 diag::note_ovl_candidate_unsatisfied_constraints)
10841 << TemplateArgString;
10842
10843 S.DiagnoseUnsatisfiedConstraint(
10844 static_cast<CNSInfo*>(DeductionFailure.Data)->Satisfaction);
10845 return;
10846 }
10847 case Sema::TDK_TooManyArguments:
10848 case Sema::TDK_TooFewArguments:
10849 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
10850 return;
10851
10852 case Sema::TDK_InstantiationDepth:
10853 S.Diag(Templated->getLocation(),
10854 diag::note_ovl_candidate_instantiation_depth);
10855 MaybeEmitInheritedConstructorNote(S, Found);
10856 return;
10857
10858 case Sema::TDK_SubstitutionFailure: {
10859 // Format the template argument list into the argument string.
10860 SmallString<128> TemplateArgString;
10861 if (TemplateArgumentList *Args =
10862 DeductionFailure.getTemplateArgumentList()) {
10863 TemplateArgString = " ";
10864 TemplateArgString += S.getTemplateArgumentBindingsText(
10865 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10866 if (TemplateArgString.size() == 1)
10867 TemplateArgString.clear();
10868 }
10869
10870 // If this candidate was disabled by enable_if, say so.
10871 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
10872 if (PDiag && PDiag->second.getDiagID() ==
10873 diag::err_typename_nested_not_found_enable_if) {
10874 // FIXME: Use the source range of the condition, and the fully-qualified
10875 // name of the enable_if template. These are both present in PDiag.
10876 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
10877 << "'enable_if'" << TemplateArgString;
10878 return;
10879 }
10880
10881 // We found a specific requirement that disabled the enable_if.
10882 if (PDiag && PDiag->second.getDiagID() ==
10883 diag::err_typename_nested_not_found_requirement) {
10884 S.Diag(Templated->getLocation(),
10885 diag::note_ovl_candidate_disabled_by_requirement)
10886 << PDiag->second.getStringArg(0) << TemplateArgString;
10887 return;
10888 }
10889
10890 // Format the SFINAE diagnostic into the argument string.
10891 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
10892 // formatted message in another diagnostic.
10893 SmallString<128> SFINAEArgString;
10894 SourceRange R;
10895 if (PDiag) {
10896 SFINAEArgString = ": ";
10897 R = SourceRange(PDiag->first, PDiag->first);
10898 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
10899 }
10900
10901 S.Diag(Templated->getLocation(),
10902 diag::note_ovl_candidate_substitution_failure)
10903 << TemplateArgString << SFINAEArgString << R;
10904 MaybeEmitInheritedConstructorNote(S, Found);
10905 return;
10906 }
10907
10908 case Sema::TDK_DeducedMismatch:
10909 case Sema::TDK_DeducedMismatchNested: {
10910 // Format the template argument list into the argument string.
10911 SmallString<128> TemplateArgString;
10912 if (TemplateArgumentList *Args =
10913 DeductionFailure.getTemplateArgumentList()) {
10914 TemplateArgString = " ";
10915 TemplateArgString += S.getTemplateArgumentBindingsText(
10916 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10917 if (TemplateArgString.size() == 1)
10918 TemplateArgString.clear();
10919 }
10920
10921 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
10922 << (*DeductionFailure.getCallArgIndex() + 1)
10923 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
10924 << TemplateArgString
10925 << (DeductionFailure.Result == Sema::TDK_DeducedMismatchNested);
10926 break;
10927 }
10928
10929 case Sema::TDK_NonDeducedMismatch: {
10930 // FIXME: Provide a source location to indicate what we couldn't match.
10931 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
10932 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
10933 if (FirstTA.getKind() == TemplateArgument::Template &&
10934 SecondTA.getKind() == TemplateArgument::Template) {
10935 TemplateName FirstTN = FirstTA.getAsTemplate();
10936 TemplateName SecondTN = SecondTA.getAsTemplate();
10937 if (FirstTN.getKind() == TemplateName::Template &&
10938 SecondTN.getKind() == TemplateName::Template) {
10939 if (FirstTN.getAsTemplateDecl()->getName() ==
10940 SecondTN.getAsTemplateDecl()->getName()) {
10941 // FIXME: This fixes a bad diagnostic where both templates are named
10942 // the same. This particular case is a bit difficult since:
10943 // 1) It is passed as a string to the diagnostic printer.
10944 // 2) The diagnostic printer only attempts to find a better
10945 // name for types, not decls.
10946 // Ideally, this should folded into the diagnostic printer.
10947 S.Diag(Templated->getLocation(),
10948 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
10949 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
10950 return;
10951 }
10952 }
10953 }
10954
10955 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
10956 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
10957 return;
10958
10959 // FIXME: For generic lambda parameters, check if the function is a lambda
10960 // call operator, and if so, emit a prettier and more informative
10961 // diagnostic that mentions 'auto' and lambda in addition to
10962 // (or instead of?) the canonical template type parameters.
10963 S.Diag(Templated->getLocation(),
10964 diag::note_ovl_candidate_non_deduced_mismatch)
10965 << FirstTA << SecondTA;
10966 return;
10967 }
10968 // TODO: diagnose these individually, then kill off
10969 // note_ovl_candidate_bad_deduction, which is uselessly vague.
10970 case Sema::TDK_MiscellaneousDeductionFailure:
10971 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
10972 MaybeEmitInheritedConstructorNote(S, Found);
10973 return;
10974 case Sema::TDK_CUDATargetMismatch:
10975 S.Diag(Templated->getLocation(),
10976 diag::note_cuda_ovl_candidate_target_mismatch);
10977 return;
10978 }
10979}
10980
10981/// Diagnose a failed template-argument deduction, for function calls.
10982static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
10983 unsigned NumArgs,
10984 bool TakingCandidateAddress) {
10985 unsigned TDK = Cand->DeductionFailure.Result;
10986 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
10987 if (CheckArityMismatch(S, Cand, NumArgs))
10988 return;
10989 }
10990 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
10991 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
10992}
10993
10994/// CUDA: diagnose an invalid call across targets.
10995static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
10996 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
10997 FunctionDecl *Callee = Cand->Function;
10998
10999 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
11000 CalleeTarget = S.IdentifyCUDATarget(Callee);
11001
11002 std::string FnDesc;
11003 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
11004 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee,
11005 Cand->getRewriteKind(), FnDesc);
11006
11007 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
11008 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
11009 << FnDesc /* Ignored */
11010 << CalleeTarget << CallerTarget;
11011
11012 // This could be an implicit constructor for which we could not infer the
11013 // target due to a collsion. Diagnose that case.
11014 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
11015 if (Meth != nullptr && Meth->isImplicit()) {
11016 CXXRecordDecl *ParentClass = Meth->getParent();
11017 Sema::CXXSpecialMember CSM;
11018
11019 switch (FnKindPair.first) {
11020 default:
11021 return;
11022 case oc_implicit_default_constructor:
11023 CSM = Sema::CXXDefaultConstructor;
11024 break;
11025 case oc_implicit_copy_constructor:
11026 CSM = Sema::CXXCopyConstructor;
11027 break;
11028 case oc_implicit_move_constructor:
11029 CSM = Sema::CXXMoveConstructor;
11030 break;
11031 case oc_implicit_copy_assignment:
11032 CSM = Sema::CXXCopyAssignment;
11033 break;
11034 case oc_implicit_move_assignment:
11035 CSM = Sema::CXXMoveAssignment;
11036 break;
11037 };
11038
11039 bool ConstRHS = false;
11040 if (Meth->getNumParams()) {
11041 if (const ReferenceType *RT =
11042 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
11043 ConstRHS = RT->getPointeeType().isConstQualified();
11044 }
11045 }
11046
11047 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
11048 /* ConstRHS */ ConstRHS,
11049 /* Diagnose */ true);
11050 }
11051}
11052
11053static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
11054 FunctionDecl *Callee = Cand->Function;
11055 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
11056
11057 S.Diag(Callee->getLocation(),
11058 diag::note_ovl_candidate_disabled_by_function_cond_attr)
11059 << Attr->getCond()->getSourceRange() << Attr->getMessage();
11060}
11061
11062static void DiagnoseFailedExplicitSpec(Sema &S, OverloadCandidate *Cand) {
11063 ExplicitSpecifier ES = ExplicitSpecifier::getFromDecl(Cand->Function);
11064 assert(ES.isExplicit() && "not an explicit candidate");
11065
11066 unsigned Kind;
11067 switch (Cand->Function->getDeclKind()) {
11068 case Decl::Kind::CXXConstructor:
11069 Kind = 0;
11070 break;
11071 case Decl::Kind::CXXConversion:
11072 Kind = 1;
11073 break;
11074 case Decl::Kind::CXXDeductionGuide:
11075 Kind = Cand->Function->isImplicit() ? 0 : 2;
11076 break;
11077 default:
11078 llvm_unreachable("invalid Decl");
11079 }
11080
11081 // Note the location of the first (in-class) declaration; a redeclaration
11082 // (particularly an out-of-class definition) will typically lack the
11083 // 'explicit' specifier.
11084 // FIXME: This is probably a good thing to do for all 'candidate' notes.
11085 FunctionDecl *First = Cand->Function->getFirstDecl();
11086 if (FunctionDecl *Pattern = First->getTemplateInstantiationPattern())
11087 First = Pattern->getFirstDecl();
11088
11089 S.Diag(First->getLocation(),
11090 diag::note_ovl_candidate_explicit)
11091 << Kind << (ES.getExpr() ? 1 : 0)
11092 << (ES.getExpr() ? ES.getExpr()->getSourceRange() : SourceRange());
11093}
11094
11095static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
11096 FunctionDecl *Callee = Cand->Function;
11097
11098 S.Diag(Callee->getLocation(),
11099 diag::note_ovl_candidate_disabled_by_extension)
11100 << S.getOpenCLExtensionsFromDeclExtMap(Callee);
11101}
11102
11103/// Generates a 'note' diagnostic for an overload candidate. We've
11104/// already generated a primary error at the call site.
11105///
11106/// It really does need to be a single diagnostic with its caret
11107/// pointed at the candidate declaration. Yes, this creates some
11108/// major challenges of technical writing. Yes, this makes pointing
11109/// out problems with specific arguments quite awkward. It's still
11110/// better than generating twenty screens of text for every failed
11111/// overload.
11112///
11113/// It would be great to be able to express per-candidate problems
11114/// more richly for those diagnostic clients that cared, but we'd
11115/// still have to be just as careful with the default diagnostics.
11116/// \param CtorDestAS Addr space of object being constructed (for ctor
11117/// candidates only).
11118static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
11119 unsigned NumArgs,
11120 bool TakingCandidateAddress,
11121 LangAS CtorDestAS = LangAS::Default) {
11122 FunctionDecl *Fn = Cand->Function;
11123 if (shouldSkipNotingLambdaConversionDecl(Fn))
11124 return;
11125
11126 // Note deleted candidates, but only if they're viable.
11127 if (Cand->Viable) {
11128 if (Fn->isDeleted()) {
11129 std::string FnDesc;
11130 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
11131 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn,
11132 Cand->getRewriteKind(), FnDesc);
11133
11134 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
11135 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
11136 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
11137 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
11138 return;
11139 }
11140
11141 // We don't really have anything else to say about viable candidates.
11142 S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
11143 return;
11144 }
11145
11146 switch (Cand->FailureKind) {
11147 case ovl_fail_too_many_arguments:
11148 case ovl_fail_too_few_arguments:
11149 return DiagnoseArityMismatch(S, Cand, NumArgs);
11150
11151 case ovl_fail_bad_deduction:
11152 return DiagnoseBadDeduction(S, Cand, NumArgs,
11153 TakingCandidateAddress);
11154
11155 case ovl_fail_illegal_constructor: {
11156 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
11157 << (Fn->getPrimaryTemplate() ? 1 : 0);
11158 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
11159 return;
11160 }
11161
11162 case ovl_fail_object_addrspace_mismatch: {
11163 Qualifiers QualsForPrinting;
11164 QualsForPrinting.setAddressSpace(CtorDestAS);
11165 S.Diag(Fn->getLocation(),
11166 diag::note_ovl_candidate_illegal_constructor_adrspace_mismatch)
11167 << QualsForPrinting;
11168 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
11169 return;
11170 }
11171
11172 case ovl_fail_trivial_conversion:
11173 case ovl_fail_bad_final_conversion:
11174 case ovl_fail_final_conversion_not_exact:
11175 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
11176
11177 case ovl_fail_bad_conversion: {
11178 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
11179 for (unsigned N = Cand->Conversions.size(); I != N; ++I)
11180 if (Cand->Conversions[I].isBad())
11181 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
11182
11183 // FIXME: this currently happens when we're called from SemaInit
11184 // when user-conversion overload fails. Figure out how to handle
11185 // those conditions and diagnose them well.
11186 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
11187 }
11188
11189 case ovl_fail_bad_target:
11190 return DiagnoseBadTarget(S, Cand);
11191
11192 case ovl_fail_enable_if:
11193 return DiagnoseFailedEnableIfAttr(S, Cand);
11194
11195 case ovl_fail_explicit:
11196 return DiagnoseFailedExplicitSpec(S, Cand);
11197
11198 case ovl_fail_ext_disabled:
11199 return DiagnoseOpenCLExtensionDisabled(S, Cand);
11200
11201 case ovl_fail_inhctor_slice:
11202 // It's generally not interesting to note copy/move constructors here.
11203 if (cast<CXXConstructorDecl>(Fn)->isCopyOrMoveConstructor())
11204 return;
11205 S.Diag(Fn->getLocation(),
11206 diag::note_ovl_candidate_inherited_constructor_slice)
11207 << (Fn->getPrimaryTemplate() ? 1 : 0)
11208 << Fn->getParamDecl(0)->getType()->isRValueReferenceType();
11209 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
11210 return;
11211
11212 case ovl_fail_addr_not_available: {
11213 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
11214 (void)Available;
11215 assert(!Available);
11216 break;
11217 }
11218 case ovl_non_default_multiversion_function:
11219 // Do nothing, these should simply be ignored.
11220 break;
11221
11222 case ovl_fail_constraints_not_satisfied: {
11223 std::string FnDesc;
11224 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
11225 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn,
11226 Cand->getRewriteKind(), FnDesc);
11227
11228 S.Diag(Fn->getLocation(),
11229 diag::note_ovl_candidate_constraints_not_satisfied)
11230 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
11231 << FnDesc /* Ignored */;
11232 ConstraintSatisfaction Satisfaction;
11233 if (S.CheckFunctionConstraints(Fn, Satisfaction))
11234 break;
11235 S.DiagnoseUnsatisfiedConstraint(Satisfaction);
11236 }
11237 }
11238}
11239
11240static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
11241 if (shouldSkipNotingLambdaConversionDecl(Cand->Surrogate))
11242 return;
11243
11244 // Desugar the type of the surrogate down to a function type,
11245 // retaining as many typedefs as possible while still showing
11246 // the function type (and, therefore, its parameter types).
11247 QualType FnType = Cand->Surrogate->getConversionType();
11248 bool isLValueReference = false;
11249 bool isRValueReference = false;
11250 bool isPointer = false;
11251 if (const LValueReferenceType *FnTypeRef =
11252 FnType->getAs<LValueReferenceType>()) {
11253 FnType = FnTypeRef->getPointeeType();
11254 isLValueReference = true;
11255 } else if (const RValueReferenceType *FnTypeRef =
11256 FnType->getAs<RValueReferenceType>()) {
11257 FnType = FnTypeRef->getPointeeType();
11258 isRValueReference = true;
11259 }
11260 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
11261 FnType = FnTypePtr->getPointeeType();
11262 isPointer = true;
11263 }
11264 // Desugar down to a function type.
11265 FnType = QualType(FnType->getAs<FunctionType>(), 0);
11266 // Reconstruct the pointer/reference as appropriate.
11267 if (isPointer) FnType = S.Context.getPointerType(FnType);
11268 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
11269 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
11270
11271 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
11272 << FnType;
11273}
11274
11275static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
11276 SourceLocation OpLoc,
11277 OverloadCandidate *Cand) {
11278 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
11279 std::string TypeStr("operator");
11280 TypeStr += Opc;
11281 TypeStr += "(";
11282 TypeStr += Cand->BuiltinParamTypes[0].getAsString();
11283 if (Cand->Conversions.size() == 1) {
11284 TypeStr += ")";
11285 S.Diag(OpLoc, diag::note_ovl_builtin_candidate) << TypeStr;
11286 } else {
11287 TypeStr += ", ";
11288 TypeStr += Cand->BuiltinParamTypes[1].getAsString();
11289 TypeStr += ")";
11290 S.Diag(OpLoc, diag::note_ovl_builtin_candidate) << TypeStr;
11291 }
11292}
11293
11294static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
11295 OverloadCandidate *Cand) {
11296 for (const ImplicitConversionSequence &ICS : Cand->Conversions) {
11297 if (ICS.isBad()) break; // all meaningless after first invalid
11298 if (!ICS.isAmbiguous()) continue;
11299
11300 ICS.DiagnoseAmbiguousConversion(
11301 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
11302 }
11303}
11304
11305static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
11306 if (Cand->Function)
11307 return Cand->Function->getLocation();
11308 if (Cand->IsSurrogate)
11309 return Cand->Surrogate->getLocation();
11310 return SourceLocation();
11311}
11312
11313static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
11314 switch ((Sema::TemplateDeductionResult)DFI.Result) {
11315 case Sema::TDK_Success:
11316 case Sema::TDK_NonDependentConversionFailure:
11317 llvm_unreachable("non-deduction failure while diagnosing bad deduction");
11318
11319 case Sema::TDK_Invalid:
11320 case Sema::TDK_Incomplete:
11321 case Sema::TDK_IncompletePack:
11322 return 1;
11323
11324 case Sema::TDK_Underqualified:
11325 case Sema::TDK_Inconsistent:
11326 return 2;
11327
11328 case Sema::TDK_SubstitutionFailure:
11329 case Sema::TDK_DeducedMismatch:
11330 case Sema::TDK_ConstraintsNotSatisfied:
11331 case Sema::TDK_DeducedMismatchNested:
11332 case Sema::TDK_NonDeducedMismatch:
11333 case Sema::TDK_MiscellaneousDeductionFailure:
11334 case Sema::TDK_CUDATargetMismatch:
11335 return 3;
11336
11337 case Sema::TDK_InstantiationDepth:
11338 return 4;
11339
11340 case Sema::TDK_InvalidExplicitArguments:
11341 return 5;
11342
11343 case Sema::TDK_TooManyArguments:
11344 case Sema::TDK_TooFewArguments:
11345 return 6;
11346 }
11347 llvm_unreachable("Unhandled deduction result");
11348}
11349
11350namespace {
11351struct CompareOverloadCandidatesForDisplay {
11352 Sema &S;
11353 SourceLocation Loc;
11354 size_t NumArgs;
11355 OverloadCandidateSet::CandidateSetKind CSK;
11356
11357 CompareOverloadCandidatesForDisplay(
11358 Sema &S, SourceLocation Loc, size_t NArgs,
11359 OverloadCandidateSet::CandidateSetKind CSK)
11360 : S(S), NumArgs(NArgs), CSK(CSK) {}
11361
11362 OverloadFailureKind EffectiveFailureKind(const OverloadCandidate *C) const {
11363 // If there are too many or too few arguments, that's the high-order bit we
11364 // want to sort by, even if the immediate failure kind was something else.
11365 if (C->FailureKind == ovl_fail_too_many_arguments ||
11366 C->FailureKind == ovl_fail_too_few_arguments)
11367 return static_cast<OverloadFailureKind>(C->FailureKind);
11368
11369 if (C->Function) {
11370 if (NumArgs > C->Function->getNumParams() && !C->Function->isVariadic())
11371 return ovl_fail_too_many_arguments;
11372 if (NumArgs < C->Function->getMinRequiredArguments())
11373 return ovl_fail_too_few_arguments;
11374 }
11375
11376 return static_cast<OverloadFailureKind>(C->FailureKind);
11377 }
11378
11379 bool operator()(const OverloadCandidate *L,
11380 const OverloadCandidate *R) {
11381 // Fast-path this check.
11382 if (L == R) return false;
11383
11384 // Order first by viability.
11385 if (L->Viable) {
11386 if (!R->Viable) return true;
11387
11388 // TODO: introduce a tri-valued comparison for overload
11389 // candidates. Would be more worthwhile if we had a sort
11390 // that could exploit it.
11391 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation(), CSK))
11392 return true;
11393 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation(), CSK))
11394 return false;
11395 } else if (R->Viable)
11396 return false;
11397
11398 assert(L->Viable == R->Viable);
11399
11400 // Criteria by which we can sort non-viable candidates:
11401 if (!L->Viable) {
11402 OverloadFailureKind LFailureKind = EffectiveFailureKind(L);
11403 OverloadFailureKind RFailureKind = EffectiveFailureKind(R);
11404
11405 // 1. Arity mismatches come after other candidates.
11406 if (LFailureKind == ovl_fail_too_many_arguments ||
11407 LFailureKind == ovl_fail_too_few_arguments) {
11408 if (RFailureKind == ovl_fail_too_many_arguments ||
11409 RFailureKind == ovl_fail_too_few_arguments) {
11410 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
11411 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
11412 if (LDist == RDist) {
11413 if (LFailureKind == RFailureKind)
11414 // Sort non-surrogates before surrogates.
11415 return !L->IsSurrogate && R->IsSurrogate;
11416 // Sort candidates requiring fewer parameters than there were
11417 // arguments given after candidates requiring more parameters
11418 // than there were arguments given.
11419 return LFailureKind == ovl_fail_too_many_arguments;
11420 }
11421 return LDist < RDist;
11422 }
11423 return false;
11424 }
11425 if (RFailureKind == ovl_fail_too_many_arguments ||
11426 RFailureKind == ovl_fail_too_few_arguments)
11427 return true;
11428
11429 // 2. Bad conversions come first and are ordered by the number
11430 // of bad conversions and quality of good conversions.
11431 if (LFailureKind == ovl_fail_bad_conversion) {
11432 if (RFailureKind != ovl_fail_bad_conversion)
11433 return true;
11434
11435 // The conversion that can be fixed with a smaller number of changes,
11436 // comes first.
11437 unsigned numLFixes = L->Fix.NumConversionsFixed;
11438 unsigned numRFixes = R->Fix.NumConversionsFixed;
11439 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
11440 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
11441 if (numLFixes != numRFixes) {
11442 return numLFixes < numRFixes;
11443 }
11444
11445 // If there's any ordering between the defined conversions...
11446 // FIXME: this might not be transitive.
11447 assert(L->Conversions.size() == R->Conversions.size());
11448
11449 int leftBetter = 0;
11450 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
11451 for (unsigned E = L->Conversions.size(); I != E; ++I) {
11452 switch (CompareImplicitConversionSequences(S, Loc,
11453 L->Conversions[I],
11454 R->Conversions[I])) {
11455 case ImplicitConversionSequence::Better:
11456 leftBetter++;
11457 break;
11458
11459 case ImplicitConversionSequence::Worse:
11460 leftBetter--;
11461 break;
11462
11463 case ImplicitConversionSequence::Indistinguishable:
11464 break;
11465 }
11466 }
11467 if (leftBetter > 0) return true;
11468 if (leftBetter < 0) return false;
11469
11470 } else if (RFailureKind == ovl_fail_bad_conversion)
11471 return false;
11472
11473 if (LFailureKind == ovl_fail_bad_deduction) {
11474 if (RFailureKind != ovl_fail_bad_deduction)
11475 return true;
11476
11477 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
11478 return RankDeductionFailure(L->DeductionFailure)
11479 < RankDeductionFailure(R->DeductionFailure);
11480 } else if (RFailureKind == ovl_fail_bad_deduction)
11481 return false;
11482
11483 // TODO: others?
11484 }
11485
11486 // Sort everything else by location.
11487 SourceLocation LLoc = GetLocationForCandidate(L);
11488 SourceLocation RLoc = GetLocationForCandidate(R);
11489
11490 // Put candidates without locations (e.g. builtins) at the end.
11491 if (LLoc.isInvalid()) return false;
11492 if (RLoc.isInvalid()) return true;
11493
11494 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
11495 }
11496};
11497}
11498
11499/// CompleteNonViableCandidate - Normally, overload resolution only
11500/// computes up to the first bad conversion. Produces the FixIt set if
11501/// possible.
11502static void
11503CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
11504 ArrayRef<Expr *> Args,
11505 OverloadCandidateSet::CandidateSetKind CSK) {
11506 assert(!Cand->Viable);
11507
11508 // Don't do anything on failures other than bad conversion.
11509 if (Cand->FailureKind != ovl_fail_bad_conversion)
11510 return;
11511
11512 // We only want the FixIts if all the arguments can be corrected.
11513 bool Unfixable = false;
11514 // Use a implicit copy initialization to check conversion fixes.
11515 Cand->Fix.setConversionChecker(TryCopyInitialization);
11516
11517 // Attempt to fix the bad conversion.
11518 unsigned ConvCount = Cand->Conversions.size();
11519 for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/;
11520 ++ConvIdx) {
11521 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
11522 if (Cand->Conversions[ConvIdx].isInitialized() &&
11523 Cand->Conversions[ConvIdx].isBad()) {
11524 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
11525 break;
11526 }
11527 }
11528
11529 // FIXME: this should probably be preserved from the overload
11530 // operation somehow.
11531 bool SuppressUserConversions = false;
11532
11533 unsigned ConvIdx = 0;
11534 unsigned ArgIdx = 0;
11535 ArrayRef<QualType> ParamTypes;
11536 bool Reversed = Cand->isReversed();
11537
11538 if (Cand->IsSurrogate) {
11539 QualType ConvType
11540 = Cand->Surrogate->getConversionType().getNonReferenceType();
11541 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
11542 ConvType = ConvPtrType->getPointeeType();
11543 ParamTypes = ConvType->castAs<FunctionProtoType>()->getParamTypes();
11544 // Conversion 0 is 'this', which doesn't have a corresponding parameter.
11545 ConvIdx = 1;
11546 } else if (Cand->Function) {
11547 ParamTypes =
11548 Cand->Function->getType()->castAs<FunctionProtoType>()->getParamTypes();
11549 if (isa<CXXMethodDecl>(Cand->Function) &&
11550 !isa<CXXConstructorDecl>(Cand->Function) && !Reversed) {
11551 // Conversion 0 is 'this', which doesn't have a corresponding parameter.
11552 ConvIdx = 1;
11553 if (CSK == OverloadCandidateSet::CSK_Operator &&
11554 Cand->Function->getDeclName().getCXXOverloadedOperator() != OO_Call)
11555 // Argument 0 is 'this', which doesn't have a corresponding parameter.
11556 ArgIdx = 1;
11557 }
11558 } else {
11559 // Builtin operator.
11560 assert(ConvCount <= 3);
11561 ParamTypes = Cand->BuiltinParamTypes;
11562 }
11563
11564 // Fill in the rest of the conversions.
11565 for (unsigned ParamIdx = Reversed ? ParamTypes.size() - 1 : 0;
11566 ConvIdx != ConvCount;
11567 ++ConvIdx, ++ArgIdx, ParamIdx += (Reversed ? -1 : 1)) {
11568 assert(ArgIdx < Args.size() && "no argument for this arg conversion");
11569 if (Cand->Conversions[ConvIdx].isInitialized()) {
11570 // We've already checked this conversion.
11571 } else if (ParamIdx < ParamTypes.size()) {
11572 if (ParamTypes[ParamIdx]->isDependentType())
11573 Cand->Conversions[ConvIdx].setAsIdentityConversion(
11574 Args[ArgIdx]->getType());
11575 else {
11576 Cand->Conversions[ConvIdx] =
11577 TryCopyInitialization(S, Args[ArgIdx], ParamTypes[ParamIdx],
11578 SuppressUserConversions,
11579 /*InOverloadResolution=*/true,
11580 /*AllowObjCWritebackConversion=*/
11581 S.getLangOpts().ObjCAutoRefCount);
11582 // Store the FixIt in the candidate if it exists.
11583 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
11584 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
11585 }
11586 } else
11587 Cand->Conversions[ConvIdx].setEllipsis();
11588 }
11589}
11590
11591SmallVector<OverloadCandidate *, 32> OverloadCandidateSet::CompleteCandidates(
11592 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
11593 SourceLocation OpLoc,
11594 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
11595 // Sort the candidates by viability and position. Sorting directly would
11596 // be prohibitive, so we make a set of pointers and sort those.
11597 SmallVector<OverloadCandidate*, 32> Cands;
11598 if (OCD == OCD_AllCandidates) Cands.reserve(size());
11599 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
11600 if (!Filter(*Cand))
11601 continue;
11602 switch (OCD) {
11603 case OCD_AllCandidates:
11604 if (!Cand->Viable) {
11605 if (!Cand->Function && !Cand->IsSurrogate) {
11606 // This a non-viable builtin candidate. We do not, in general,
11607 // want to list every possible builtin candidate.
11608 continue;
11609 }
11610 CompleteNonViableCandidate(S, Cand, Args, Kind);
11611 }
11612 break;
11613
11614 case OCD_ViableCandidates:
11615 if (!Cand->Viable)
11616 continue;
11617 break;
11618
11619 case OCD_AmbiguousCandidates:
11620 if (!Cand->Best)
11621 continue;
11622 break;
11623 }
11624
11625 Cands.push_back(Cand);
11626 }
11627
11628 llvm::stable_sort(
11629 Cands, CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size(), Kind));
11630
11631 return Cands;
11632}
11633
11634bool OverloadCandidateSet::shouldDeferDiags(Sema &S, ArrayRef<Expr *> Args,
11635 SourceLocation OpLoc) {
11636 bool DeferHint = false;
11637 if (S.getLangOpts().CUDA && S.getLangOpts().GPUDeferDiag) {
11638 // Defer diagnostic for CUDA/HIP if there are wrong-sided candidates or
11639 // host device candidates.
11640 auto WrongSidedCands =
11641 CompleteCandidates(S, OCD_AllCandidates, Args, OpLoc, [](auto &Cand) {
11642 return (Cand.Viable == false &&
11643 Cand.FailureKind == ovl_fail_bad_target) ||
11644 (Cand.Function->template hasAttr<CUDAHostAttr>() &&
11645 Cand.Function->template hasAttr<CUDADeviceAttr>());
11646 });
11647 DeferHint = WrongSidedCands.size();
11648 }
11649 return DeferHint;
11650}
11651
11652/// When overload resolution fails, prints diagnostic messages containing the
11653/// candidates in the candidate set.
11654void OverloadCandidateSet::NoteCandidates(
11655 PartialDiagnosticAt PD, Sema &S, OverloadCandidateDisplayKind OCD,
11656 ArrayRef<Expr *> Args, StringRef Opc, SourceLocation OpLoc,
11657 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
11658
11659 auto Cands = CompleteCandidates(S, OCD, Args, OpLoc, Filter);
11660
11661 S.Diag(PD.first, PD.second, shouldDeferDiags(S, Args, OpLoc));
11662
11663 NoteCandidates(S, Args, Cands, Opc, OpLoc);
11664
11665 if (OCD == OCD_AmbiguousCandidates)
11666 MaybeDiagnoseAmbiguousConstraints(S, {begin(), end()});
11667}
11668
11669void OverloadCandidateSet::NoteCandidates(Sema &S, ArrayRef<Expr *> Args,
11670 ArrayRef<OverloadCandidate *> Cands,
11671 StringRef Opc, SourceLocation OpLoc) {
11672 bool ReportedAmbiguousConversions = false;
11673
11674 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
11675 unsigned CandsShown = 0;
11676 auto I = Cands.begin(), E = Cands.end();
11677 for (; I != E; ++I) {
11678 OverloadCandidate *Cand = *I;
11679
11680 // Set an arbitrary limit on the number of candidate functions we'll spam
11681 // the user with. FIXME: This limit should depend on details of the
11682 // candidate list.
11683 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
11684 break;
11685 }
11686 ++CandsShown;
11687
11688 if (Cand->Function)
11689 NoteFunctionCandidate(S, Cand, Args.size(),
11690 /*TakingCandidateAddress=*/false, DestAS);
11691 else if (Cand->IsSurrogate)
11692 NoteSurrogateCandidate(S, Cand);
11693 else {
11694 assert(Cand->Viable &&
11695 "Non-viable built-in candidates are not added to Cands.");
11696 // Generally we only see ambiguities including viable builtin
11697 // operators if overload resolution got screwed up by an
11698 // ambiguous user-defined conversion.
11699 //
11700 // FIXME: It's quite possible for different conversions to see
11701 // different ambiguities, though.
11702 if (!ReportedAmbiguousConversions) {
11703 NoteAmbiguousUserConversions(S, OpLoc, Cand);
11704 ReportedAmbiguousConversions = true;
11705 }
11706
11707 // If this is a viable builtin, print it.
11708 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
11709 }
11710 }
11711
11712 if (I != E)
11713 S.Diag(OpLoc, diag::note_ovl_too_many_candidates,
11714 shouldDeferDiags(S, Args, OpLoc))
11715 << int(E - I);
11716}
11717
11718static SourceLocation
11719GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
11720 return Cand->Specialization ? Cand->Specialization->getLocation()
11721 : SourceLocation();
11722}
11723
11724namespace {
11725struct CompareTemplateSpecCandidatesForDisplay {
11726 Sema &S;
11727 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
11728
11729 bool operator()(const TemplateSpecCandidate *L,
11730 const TemplateSpecCandidate *R) {
11731 // Fast-path this check.
11732 if (L == R)
11733 return false;
11734
11735 // Assuming that both candidates are not matches...
11736
11737 // Sort by the ranking of deduction failures.
11738 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
11739 return RankDeductionFailure(L->DeductionFailure) <
11740 RankDeductionFailure(R->DeductionFailure);
11741
11742 // Sort everything else by location.
11743 SourceLocation LLoc = GetLocationForCandidate(L);
11744 SourceLocation RLoc = GetLocationForCandidate(R);
11745
11746 // Put candidates without locations (e.g. builtins) at the end.
11747 if (LLoc.isInvalid())
11748 return false;
11749 if (RLoc.isInvalid())
11750 return true;
11751
11752 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
11753 }
11754};
11755}
11756
11757/// Diagnose a template argument deduction failure.
11758/// We are treating these failures as overload failures due to bad
11759/// deductions.
11760void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
11761 bool ForTakingAddress) {
11762 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
11763 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
11764}
11765
11766void TemplateSpecCandidateSet::destroyCandidates() {
11767 for (iterator i = begin(), e = end(); i != e; ++i) {
11768 i->DeductionFailure.Destroy();
11769 }
11770}
11771
11772void TemplateSpecCandidateSet::clear() {
11773 destroyCandidates();
11774 Candidates.clear();
11775}
11776
11777/// NoteCandidates - When no template specialization match is found, prints
11778/// diagnostic messages containing the non-matching specializations that form
11779/// the candidate set.
11780/// This is analoguous to OverloadCandidateSet::NoteCandidates() with
11781/// OCD == OCD_AllCandidates and Cand->Viable == false.
11782void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
11783 // Sort the candidates by position (assuming no candidate is a match).
11784 // Sorting directly would be prohibitive, so we make a set of pointers
11785 // and sort those.
11786 SmallVector<TemplateSpecCandidate *, 32> Cands;
11787 Cands.reserve(size());
11788 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
11789 if (Cand->Specialization)
11790 Cands.push_back(Cand);
11791 // Otherwise, this is a non-matching builtin candidate. We do not,
11792 // in general, want to list every possible builtin candidate.
11793 }
11794
11795 llvm::sort(Cands, CompareTemplateSpecCandidatesForDisplay(S));
11796
11797 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
11798 // for generalization purposes (?).
11799 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
11800
11801 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
11802 unsigned CandsShown = 0;
11803 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
11804 TemplateSpecCandidate *Cand = *I;
11805
11806 // Set an arbitrary limit on the number of candidates we'll spam
11807 // the user with. FIXME: This limit should depend on details of the
11808 // candidate list.
11809 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
11810 break;
11811 ++CandsShown;
11812
11813 assert(Cand->Specialization &&
11814 "Non-matching built-in candidates are not added to Cands.");
11815 Cand->NoteDeductionFailure(S, ForTakingAddress);
11816 }
11817
11818 if (I != E)
11819 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
11820}
11821
11822// [PossiblyAFunctionType] --> [Return]
11823// NonFunctionType --> NonFunctionType
11824// R (A) --> R(A)
11825// R (*)(A) --> R (A)
11826// R (&)(A) --> R (A)
11827// R (S::*)(A) --> R (A)
11828QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
11829 QualType Ret = PossiblyAFunctionType;
11830 if (const PointerType *ToTypePtr =
11831 PossiblyAFunctionType->getAs<PointerType>())
11832 Ret = ToTypePtr->getPointeeType();
11833 else if (const ReferenceType *ToTypeRef =
11834 PossiblyAFunctionType->getAs<ReferenceType>())
11835 Ret = ToTypeRef->getPointeeType();
11836 else if (const MemberPointerType *MemTypePtr =
11837 PossiblyAFunctionType->getAs<MemberPointerType>())
11838 Ret = MemTypePtr->getPointeeType();
11839 Ret =
11840 Context.getCanonicalType(Ret).getUnqualifiedType();
11841 return Ret;
11842}
11843
11844static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
11845 bool Complain = true) {
11846 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
11847 S.DeduceReturnType(FD, Loc, Complain))
11848 return true;
11849
11850 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
11851 if (S.getLangOpts().CPlusPlus17 &&
11852 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
11853 !S.ResolveExceptionSpec(Loc, FPT))
11854 return true;
11855
11856 return false;
11857}
11858
11859namespace {
11860// A helper class to help with address of function resolution
11861// - allows us to avoid passing around all those ugly parameters
11862class AddressOfFunctionResolver {
11863 Sema& S;
11864 Expr* SourceExpr;
11865 const QualType& TargetType;
11866 QualType TargetFunctionType; // Extracted function type from target type
11867
11868 bool Complain;
11869 //DeclAccessPair& ResultFunctionAccessPair;
11870 ASTContext& Context;
11871
11872 bool TargetTypeIsNonStaticMemberFunction;
11873 bool FoundNonTemplateFunction;
11874 bool StaticMemberFunctionFromBoundPointer;
11875 bool HasComplained;
11876
11877 OverloadExpr::FindResult OvlExprInfo;
11878 OverloadExpr *OvlExpr;
11879 TemplateArgumentListInfo OvlExplicitTemplateArgs;
11880 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
11881 TemplateSpecCandidateSet FailedCandidates;
11882
11883public:
11884 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
11885 const QualType &TargetType, bool Complain)
11886 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
11887 Complain(Complain), Context(S.getASTContext()),
11888 TargetTypeIsNonStaticMemberFunction(
11889 !!TargetType->getAs<MemberPointerType>()),
11890 FoundNonTemplateFunction(false),
11891 StaticMemberFunctionFromBoundPointer(false),
11892 HasComplained(false),
11893 OvlExprInfo(OverloadExpr::find(SourceExpr)),
11894 OvlExpr(OvlExprInfo.Expression),
11895 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
11896 ExtractUnqualifiedFunctionTypeFromTargetType();
11897
11898 if (TargetFunctionType->isFunctionType()) {
11899 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
11900 if (!UME->isImplicitAccess() &&
11901 !S.ResolveSingleFunctionTemplateSpecialization(UME))
11902 StaticMemberFunctionFromBoundPointer = true;
11903 } else if (OvlExpr->hasExplicitTemplateArgs()) {
11904 DeclAccessPair dap;
11905 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
11906 OvlExpr, false, &dap)) {
11907 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
11908 if (!Method->isStatic()) {
11909 // If the target type is a non-function type and the function found
11910 // is a non-static member function, pretend as if that was the
11911 // target, it's the only possible type to end up with.
11912 TargetTypeIsNonStaticMemberFunction = true;
11913
11914 // And skip adding the function if its not in the proper form.
11915 // We'll diagnose this due to an empty set of functions.
11916 if (!OvlExprInfo.HasFormOfMemberPointer)
11917 return;
11918 }
11919
11920 Matches.push_back(std::make_pair(dap, Fn));
11921 }
11922 return;
11923 }
11924
11925 if (OvlExpr->hasExplicitTemplateArgs())
11926 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
11927
11928 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
11929 // C++ [over.over]p4:
11930 // If more than one function is selected, [...]
11931 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
11932 if (FoundNonTemplateFunction)
11933 EliminateAllTemplateMatches();
11934 else
11935 EliminateAllExceptMostSpecializedTemplate();
11936 }
11937 }
11938
11939 if (S.getLangOpts().CUDA && Matches.size() > 1)
11940 EliminateSuboptimalCudaMatches();
11941 }
11942
11943 bool hasComplained() const { return HasComplained; }
11944
11945private:
11946 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
11947 QualType Discard;
11948 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
11949 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
11950 }
11951
11952 /// \return true if A is considered a better overload candidate for the
11953 /// desired type than B.
11954 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
11955 // If A doesn't have exactly the correct type, we don't want to classify it
11956 // as "better" than anything else. This way, the user is required to
11957 // disambiguate for us if there are multiple candidates and no exact match.
11958 return candidateHasExactlyCorrectType(A) &&
11959 (!candidateHasExactlyCorrectType(B) ||
11960 compareEnableIfAttrs(S, A, B) == Comparison::Better);
11961 }
11962
11963 /// \return true if we were able to eliminate all but one overload candidate,
11964 /// false otherwise.
11965 bool eliminiateSuboptimalOverloadCandidates() {
11966 // Same algorithm as overload resolution -- one pass to pick the "best",
11967 // another pass to be sure that nothing is better than the best.
11968 auto Best = Matches.begin();
11969 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
11970 if (isBetterCandidate(I->second, Best->second))
11971 Best = I;
11972
11973 const FunctionDecl *BestFn = Best->second;
11974 auto IsBestOrInferiorToBest = [this, BestFn](
11975 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
11976 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
11977 };
11978
11979 // Note: We explicitly leave Matches unmodified if there isn't a clear best
11980 // option, so we can potentially give the user a better error
11981 if (!llvm::all_of(Matches, IsBestOrInferiorToBest))
11982 return false;
11983 Matches[0] = *Best;
11984 Matches.resize(1);
11985 return true;
11986 }
11987
11988 bool isTargetTypeAFunction() const {
11989 return TargetFunctionType->isFunctionType();
11990 }
11991
11992 // [ToType] [Return]
11993
11994 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
11995 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
11996 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
11997 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
11998 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
11999 }
12000
12001 // return true if any matching specializations were found
12002 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
12003 const DeclAccessPair& CurAccessFunPair) {
12004 if (CXXMethodDecl *Method
12005 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
12006 // Skip non-static function templates when converting to pointer, and
12007 // static when converting to member pointer.
12008 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
12009 return false;
12010 }
12011 else if (TargetTypeIsNonStaticMemberFunction)
12012 return false;
12013
12014 // C++ [over.over]p2:
12015 // If the name is a function template, template argument deduction is
12016 // done (14.8.2.2), and if the argument deduction succeeds, the
12017 // resulting template argument list is used to generate a single
12018 // function template specialization, which is added to the set of
12019 // overloaded functions considered.
12020 FunctionDecl *Specialization = nullptr;
12021 TemplateDeductionInfo Info(FailedCandidates.getLocation());
12022 if (Sema::TemplateDeductionResult Result
12023 = S.DeduceTemplateArguments(FunctionTemplate,
12024 &OvlExplicitTemplateArgs,
12025 TargetFunctionType, Specialization,
12026 Info, /*IsAddressOfFunction*/true)) {
12027 // Make a note of the failed deduction for diagnostics.
12028 FailedCandidates.addCandidate()
12029 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
12030 MakeDeductionFailureInfo(Context, Result, Info));
12031 return false;
12032 }
12033
12034 // Template argument deduction ensures that we have an exact match or
12035 // compatible pointer-to-function arguments that would be adjusted by ICS.
12036 // This function template specicalization works.
12037 assert(S.isSameOrCompatibleFunctionType(
12038 Context.getCanonicalType(Specialization->getType()),
12039 Context.getCanonicalType(TargetFunctionType)));
12040
12041 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
12042 return false;
12043
12044 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
12045 return true;
12046 }
12047
12048 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
12049 const DeclAccessPair& CurAccessFunPair) {
12050 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
12051 // Skip non-static functions when converting to pointer, and static
12052 // when converting to member pointer.
12053 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
12054 return false;
12055 }
12056 else if (TargetTypeIsNonStaticMemberFunction)
12057 return false;
12058
12059 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
12060 if (S.getLangOpts().CUDA)
12061 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
12062 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
12063 return false;
12064 if (FunDecl->isMultiVersion()) {
12065 const auto *TA = FunDecl->getAttr<TargetAttr>();
12066 if (TA && !TA->isDefaultVersion())
12067 return false;
12068 }
12069
12070 // If any candidate has a placeholder return type, trigger its deduction
12071 // now.
12072 if (completeFunctionType(S, FunDecl, SourceExpr->getBeginLoc(),
12073 Complain)) {
12074 HasComplained |= Complain;
12075 return false;
12076 }
12077
12078 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
12079 return false;
12080
12081 // If we're in C, we need to support types that aren't exactly identical.
12082 if (!S.getLangOpts().CPlusPlus ||
12083 candidateHasExactlyCorrectType(FunDecl)) {
12084 Matches.push_back(std::make_pair(
12085 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
12086 FoundNonTemplateFunction = true;
12087 return true;
12088 }
12089 }
12090
12091 return false;
12092 }
12093
12094 bool FindAllFunctionsThatMatchTargetTypeExactly() {
12095 bool Ret = false;
12096
12097 // If the overload expression doesn't have the form of a pointer to
12098 // member, don't try to convert it to a pointer-to-member type.
12099 if (IsInvalidFormOfPointerToMemberFunction())
12100 return false;
12101
12102 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
12103 E = OvlExpr->decls_end();
12104 I != E; ++I) {
12105 // Look through any using declarations to find the underlying function.
12106 NamedDecl *Fn = (*I)->getUnderlyingDecl();
12107
12108 // C++ [over.over]p3:
12109 // Non-member functions and static member functions match
12110 // targets of type "pointer-to-function" or "reference-to-function."
12111 // Nonstatic member functions match targets of
12112 // type "pointer-to-member-function."
12113 // Note that according to DR 247, the containing class does not matter.
12114 if (FunctionTemplateDecl *FunctionTemplate
12115 = dyn_cast<FunctionTemplateDecl>(Fn)) {
12116 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
12117 Ret = true;
12118 }
12119 // If we have explicit template arguments supplied, skip non-templates.
12120 else if (!OvlExpr->hasExplicitTemplateArgs() &&
12121 AddMatchingNonTemplateFunction(Fn, I.getPair()))
12122 Ret = true;
12123 }
12124 assert(Ret || Matches.empty());
12125 return Ret;
12126 }
12127
12128 void EliminateAllExceptMostSpecializedTemplate() {
12129 // [...] and any given function template specialization F1 is
12130 // eliminated if the set contains a second function template
12131 // specialization whose function template is more specialized
12132 // than the function template of F1 according to the partial
12133 // ordering rules of 14.5.5.2.
12134
12135 // The algorithm specified above is quadratic. We instead use a
12136 // two-pass algorithm (similar to the one used to identify the
12137 // best viable function in an overload set) that identifies the
12138 // best function template (if it exists).
12139
12140 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
12141 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
12142 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
12143
12144 // TODO: It looks like FailedCandidates does not serve much purpose
12145 // here, since the no_viable diagnostic has index 0.
12146 UnresolvedSetIterator Result = S.getMostSpecialized(
12147 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
12148 SourceExpr->getBeginLoc(), S.PDiag(),
12149 S.PDiag(diag::err_addr_ovl_ambiguous)
12150 << Matches[0].second->getDeclName(),
12151 S.PDiag(diag::note_ovl_candidate)
12152 << (unsigned)oc_function << (unsigned)ocs_described_template,
12153 Complain, TargetFunctionType);
12154
12155 if (Result != MatchesCopy.end()) {
12156 // Make it the first and only element
12157 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
12158 Matches[0].second = cast<FunctionDecl>(*Result);
12159 Matches.resize(1);
12160 } else
12161 HasComplained |= Complain;
12162 }
12163
12164 void EliminateAllTemplateMatches() {
12165 // [...] any function template specializations in the set are
12166 // eliminated if the set also contains a non-template function, [...]
12167 for (unsigned I = 0, N = Matches.size(); I != N; ) {
12168 if (Matches[I].second->getPrimaryTemplate() == nullptr)
12169 ++I;
12170 else {
12171 Matches[I] = Matches[--N];
12172 Matches.resize(N);
12173 }
12174 }
12175 }
12176
12177 void EliminateSuboptimalCudaMatches() {
12178 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
12179 }
12180
12181public:
12182 void ComplainNoMatchesFound() const {
12183 assert(Matches.empty());
12184 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_no_viable)
12185 << OvlExpr->getName() << TargetFunctionType
12186 << OvlExpr->getSourceRange();
12187 if (FailedCandidates.empty())
12188 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
12189 /*TakingAddress=*/true);
12190 else {
12191 // We have some deduction failure messages. Use them to diagnose
12192 // the function templates, and diagnose the non-template candidates
12193 // normally.
12194 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
12195 IEnd = OvlExpr->decls_end();
12196 I != IEnd; ++I)
12197 if (FunctionDecl *Fun =
12198 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
12199 if (!functionHasPassObjectSizeParams(Fun))
12200 S.NoteOverloadCandidate(*I, Fun, CRK_None, TargetFunctionType,
12201 /*TakingAddress=*/true);
12202 FailedCandidates.NoteCandidates(S, OvlExpr->getBeginLoc());
12203 }
12204 }
12205
12206 bool IsInvalidFormOfPointerToMemberFunction() const {
12207 return TargetTypeIsNonStaticMemberFunction &&
12208 !OvlExprInfo.HasFormOfMemberPointer;
12209 }
12210
12211 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
12212 // TODO: Should we condition this on whether any functions might
12213 // have matched, or is it more appropriate to do that in callers?
12214 // TODO: a fixit wouldn't hurt.
12215 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
12216 << TargetType << OvlExpr->getSourceRange();
12217 }
12218
12219 bool IsStaticMemberFunctionFromBoundPointer() const {
12220 return StaticMemberFunctionFromBoundPointer;
12221 }
12222
12223 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
12224 S.Diag(OvlExpr->getBeginLoc(),
12225 diag::err_invalid_form_pointer_member_function)
12226 << OvlExpr->getSourceRange();
12227 }
12228
12229 void ComplainOfInvalidConversion() const {
12230 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_not_func_ptrref)
12231 << OvlExpr->getName() << TargetType;
12232 }
12233
12234 void ComplainMultipleMatchesFound() const {
12235 assert(Matches.size() > 1);
12236 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_ambiguous)
12237 << OvlExpr->getName() << OvlExpr->getSourceRange();
12238 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
12239 /*TakingAddress=*/true);
12240 }
12241
12242 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
12243
12244 int getNumMatches() const { return Matches.size(); }
12245
12246 FunctionDecl* getMatchingFunctionDecl() const {
12247 if (Matches.size() != 1) return nullptr;
12248 return Matches[0].second;
12249 }
12250
12251 const DeclAccessPair* getMatchingFunctionAccessPair() const {
12252 if (Matches.size() != 1) return nullptr;
12253 return &Matches[0].first;
12254 }
12255};
12256}
12257
12258/// ResolveAddressOfOverloadedFunction - Try to resolve the address of
12259/// an overloaded function (C++ [over.over]), where @p From is an
12260/// expression with overloaded function type and @p ToType is the type
12261/// we're trying to resolve to. For example:
12262///
12263/// @code
12264/// int f(double);
12265/// int f(int);
12266///
12267/// int (*pfd)(double) = f; // selects f(double)
12268/// @endcode
12269///
12270/// This routine returns the resulting FunctionDecl if it could be
12271/// resolved, and NULL otherwise. When @p Complain is true, this
12272/// routine will emit diagnostics if there is an error.
12273FunctionDecl *
12274Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
12275 QualType TargetType,
12276 bool Complain,
12277 DeclAccessPair &FoundResult,
12278 bool *pHadMultipleCandidates) {
12279 assert(AddressOfExpr->getType() == Context.OverloadTy);
12280
12281 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
12282 Complain);
12283 int NumMatches = Resolver.getNumMatches();
12284 FunctionDecl *Fn = nullptr;
12285 bool ShouldComplain = Complain && !Resolver.hasComplained();
12286 if (NumMatches == 0 && ShouldComplain) {
12287 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
12288 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
12289 else
12290 Resolver.ComplainNoMatchesFound();
12291 }
12292 else if (NumMatches > 1 && ShouldComplain)
12293 Resolver.ComplainMultipleMatchesFound();
12294 else if (NumMatches == 1) {
12295 Fn = Resolver.getMatchingFunctionDecl();
12296 assert(Fn);
12297 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
12298 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
12299 FoundResult = *Resolver.getMatchingFunctionAccessPair();
12300 if (Complain) {
12301 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
12302 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
12303 else
12304 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
12305 }
12306 }
12307
12308 if (pHadMultipleCandidates)
12309 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
12310 return Fn;
12311}
12312
12313/// Given an expression that refers to an overloaded function, try to
12314/// resolve that function to a single function that can have its address taken.
12315/// This will modify `Pair` iff it returns non-null.
12316///
12317/// This routine can only succeed if from all of the candidates in the overload
12318/// set for SrcExpr that can have their addresses taken, there is one candidate
12319/// that is more constrained than the rest.
12320FunctionDecl *
12321Sema::resolveAddressOfSingleOverloadCandidate(Expr *E, DeclAccessPair &Pair) {
12322 OverloadExpr::FindResult R = OverloadExpr::find(E);
12323 OverloadExpr *Ovl = R.Expression;
12324 bool IsResultAmbiguous = false;
12325 FunctionDecl *Result = nullptr;
12326 DeclAccessPair DAP;
12327 SmallVector<FunctionDecl *, 2> AmbiguousDecls;
12328
12329 auto CheckMoreConstrained =
12330 [&] (FunctionDecl *FD1, FunctionDecl *FD2) -> Optional<bool> {
12331 SmallVector<const Expr *, 1> AC1, AC2;
12332 FD1->getAssociatedConstraints(AC1);
12333 FD2->getAssociatedConstraints(AC2);
12334 bool AtLeastAsConstrained1, AtLeastAsConstrained2;
12335 if (IsAtLeastAsConstrained(FD1, AC1, FD2, AC2, AtLeastAsConstrained1))
12336 return None;
12337 if (IsAtLeastAsConstrained(FD2, AC2, FD1, AC1, AtLeastAsConstrained2))
12338 return None;
12339 if (AtLeastAsConstrained1 == AtLeastAsConstrained2)
12340 return None;
12341 return AtLeastAsConstrained1;
12342 };
12343
12344 // Don't use the AddressOfResolver because we're specifically looking for
12345 // cases where we have one overload candidate that lacks
12346 // enable_if/pass_object_size/...
12347 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
12348 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
12349 if (!FD)
12350 return nullptr;
12351
12352 if (!checkAddressOfFunctionIsAvailable(FD))
12353 continue;
12354
12355 // We have more than one result - see if it is more constrained than the
12356 // previous one.
12357 if (Result) {
12358 Optional<bool> MoreConstrainedThanPrevious = CheckMoreConstrained(FD,
12359 Result);
12360 if (!MoreConstrainedThanPrevious) {
12361 IsResultAmbiguous = true;
12362 AmbiguousDecls.push_back(FD);
12363 continue;
12364 }
12365 if (!*MoreConstrainedThanPrevious)
12366 continue;
12367 // FD is more constrained - replace Result with it.
12368 }
12369 IsResultAmbiguous = false;
12370 DAP = I.getPair();
12371 Result = FD;
12372 }
12373
12374 if (IsResultAmbiguous)
12375 return nullptr;
12376
12377 if (Result) {
12378 SmallVector<const Expr *, 1> ResultAC;
12379 // We skipped over some ambiguous declarations which might be ambiguous with
12380 // the selected result.
12381 for (FunctionDecl *Skipped : AmbiguousDecls)
12382 if (!CheckMoreConstrained(Skipped, Result).hasValue())
12383 return nullptr;
12384 Pair = DAP;
12385 }
12386 return Result;
12387}
12388
12389/// Given an overloaded function, tries to turn it into a non-overloaded
12390/// function reference using resolveAddressOfSingleOverloadCandidate. This
12391/// will perform access checks, diagnose the use of the resultant decl, and, if
12392/// requested, potentially perform a function-to-pointer decay.
12393///
12394/// Returns false if resolveAddressOfSingleOverloadCandidate fails.
12395/// Otherwise, returns true. This may emit diagnostics and return true.
12396bool Sema::resolveAndFixAddressOfSingleOverloadCandidate(
12397 ExprResult &SrcExpr, bool DoFunctionPointerConverion) {
12398 Expr *E = SrcExpr.get();
12399 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
12400
12401 DeclAccessPair DAP;
12402 FunctionDecl *Found = resolveAddressOfSingleOverloadCandidate(E, DAP);
12403 if (!Found || Found->isCPUDispatchMultiVersion() ||
12404 Found->isCPUSpecificMultiVersion())
12405 return false;
12406
12407 // Emitting multiple diagnostics for a function that is both inaccessible and
12408 // unavailable is consistent with our behavior elsewhere. So, always check
12409 // for both.
12410 DiagnoseUseOfDecl(Found, E->getExprLoc());
12411 CheckAddressOfMemberAccess(E, DAP);
12412 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
12413 if (DoFunctionPointerConverion && Fixed->getType()->isFunctionType())
12414 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
12415 else
12416 SrcExpr = Fixed;
12417 return true;
12418}
12419
12420/// Given an expression that refers to an overloaded function, try to
12421/// resolve that overloaded function expression down to a single function.
12422///
12423/// This routine can only resolve template-ids that refer to a single function
12424/// template, where that template-id refers to a single template whose template
12425/// arguments are either provided by the template-id or have defaults,
12426/// as described in C++0x [temp.arg.explicit]p3.
12427///
12428/// If no template-ids are found, no diagnostics are emitted and NULL is
12429/// returned.
12430FunctionDecl *
12431Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
12432 bool Complain,
12433 DeclAccessPair *FoundResult) {
12434 // C++ [over.over]p1:
12435 // [...] [Note: any redundant set of parentheses surrounding the
12436 // overloaded function name is ignored (5.1). ]
12437 // C++ [over.over]p1:
12438 // [...] The overloaded function name can be preceded by the &
12439 // operator.
12440
12441 // If we didn't actually find any template-ids, we're done.
12442 if (!ovl->hasExplicitTemplateArgs())
12443 return nullptr;
12444
12445 TemplateArgumentListInfo ExplicitTemplateArgs;
12446 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
12447 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
12448
12449 // Look through all of the overloaded functions, searching for one
12450 // whose type matches exactly.
12451 FunctionDecl *Matched = nullptr;
12452 for (UnresolvedSetIterator I = ovl->decls_begin(),
12453 E = ovl->decls_end(); I != E; ++I) {
12454 // C++0x [temp.arg.explicit]p3:
12455 // [...] In contexts where deduction is done and fails, or in contexts
12456 // where deduction is not done, if a template argument list is
12457 // specified and it, along with any default template arguments,
12458 // identifies a single function template specialization, then the
12459 // template-id is an lvalue for the function template specialization.
12460 FunctionTemplateDecl *FunctionTemplate
12461 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
12462
12463 // C++ [over.over]p2:
12464 // If the name is a function template, template argument deduction is
12465 // done (14.8.2.2), and if the argument deduction succeeds, the
12466 // resulting template argument list is used to generate a single
12467 // function template specialization, which is added to the set of
12468 // overloaded functions considered.
12469 FunctionDecl *Specialization = nullptr;
12470 TemplateDeductionInfo Info(FailedCandidates.getLocation());
12471 if (TemplateDeductionResult Result
12472 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
12473 Specialization, Info,
12474 /*IsAddressOfFunction*/true)) {
12475 // Make a note of the failed deduction for diagnostics.
12476 // TODO: Actually use the failed-deduction info?
12477 FailedCandidates.addCandidate()
12478 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
12479 MakeDeductionFailureInfo(Context, Result, Info));
12480 continue;
12481 }
12482
12483 assert(Specialization && "no specialization and no error?");
12484
12485 // Multiple matches; we can't resolve to a single declaration.
12486 if (Matched) {
12487 if (Complain) {
12488 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
12489 << ovl->getName();
12490 NoteAllOverloadCandidates(ovl);
12491 }
12492 return nullptr;
12493 }
12494
12495 Matched = Specialization;
12496 if (FoundResult) *FoundResult = I.getPair();
12497 }
12498
12499 if (Matched &&
12500 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
12501 return nullptr;
12502
12503 return Matched;
12504}
12505
12506// Resolve and fix an overloaded expression that can be resolved
12507// because it identifies a single function template specialization.
12508//
12509// Last three arguments should only be supplied if Complain = true
12510//
12511// Return true if it was logically possible to so resolve the
12512// expression, regardless of whether or not it succeeded. Always
12513// returns true if 'complain' is set.
12514bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
12515 ExprResult &SrcExpr, bool doFunctionPointerConverion,
12516 bool complain, SourceRange OpRangeForComplaining,
12517 QualType DestTypeForComplaining,
12518 unsigned DiagIDForComplaining) {
12519 assert(SrcExpr.get()->getType() == Context.OverloadTy);
12520
12521 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
12522
12523 DeclAccessPair found;
12524 ExprResult SingleFunctionExpression;
12525 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
12526 ovl.Expression, /*complain*/ false, &found)) {
12527 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getBeginLoc())) {
12528 SrcExpr = ExprError();
12529 return true;
12530 }
12531
12532 // It is only correct to resolve to an instance method if we're
12533 // resolving a form that's permitted to be a pointer to member.
12534 // Otherwise we'll end up making a bound member expression, which
12535 // is illegal in all the contexts we resolve like this.
12536 if (!ovl.HasFormOfMemberPointer &&
12537 isa<CXXMethodDecl>(fn) &&
12538 cast<CXXMethodDecl>(fn)->isInstance()) {
12539 if (!complain) return false;
12540
12541 Diag(ovl.Expression->getExprLoc(),
12542 diag::err_bound_member_function)
12543 << 0 << ovl.Expression->getSourceRange();
12544
12545 // TODO: I believe we only end up here if there's a mix of
12546 // static and non-static candidates (otherwise the expression
12547 // would have 'bound member' type, not 'overload' type).
12548 // Ideally we would note which candidate was chosen and why
12549 // the static candidates were rejected.
12550 SrcExpr = ExprError();
12551 return true;
12552 }
12553
12554 // Fix the expression to refer to 'fn'.
12555 SingleFunctionExpression =
12556 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
12557
12558 // If desired, do function-to-pointer decay.
12559 if (doFunctionPointerConverion) {
12560 SingleFunctionExpression =
12561 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
12562 if (SingleFunctionExpression.isInvalid()) {
12563 SrcExpr = ExprError();
12564 return true;
12565 }
12566 }
12567 }
12568
12569 if (!SingleFunctionExpression.isUsable()) {
12570 if (complain) {
12571 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
12572 << ovl.Expression->getName()
12573 << DestTypeForComplaining
12574 << OpRangeForComplaining
12575 << ovl.Expression->getQualifierLoc().getSourceRange();
12576 NoteAllOverloadCandidates(SrcExpr.get());
12577
12578 SrcExpr = ExprError();
12579 return true;
12580 }
12581
12582 return false;
12583 }
12584
12585 SrcExpr = SingleFunctionExpression;
12586 return true;
12587}
12588
12589/// Add a single candidate to the overload set.
12590static void AddOverloadedCallCandidate(Sema &S,
12591 DeclAccessPair FoundDecl,
12592 TemplateArgumentListInfo *ExplicitTemplateArgs,
12593 ArrayRef<Expr *> Args,
12594 OverloadCandidateSet &CandidateSet,
12595 bool PartialOverloading,
12596 bool KnownValid) {
12597 NamedDecl *Callee = FoundDecl.getDecl();
12598 if (isa<UsingShadowDecl>(Callee))
12599 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
12600
12601 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
12602 if (ExplicitTemplateArgs) {
12603 assert(!KnownValid && "Explicit template arguments?");
12604 return;
12605 }
12606 // Prevent ill-formed function decls to be added as overload candidates.
12607 if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
12608 return;
12609
12610 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
12611 /*SuppressUserConversions=*/false,
12612 PartialOverloading);
12613 return;
12614 }
12615
12616 if (FunctionTemplateDecl *FuncTemplate
12617 = dyn_cast<FunctionTemplateDecl>(Callee)) {
12618 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
12619 ExplicitTemplateArgs, Args, CandidateSet,
12620 /*SuppressUserConversions=*/false,
12621 PartialOverloading);
12622 return;
12623 }
12624
12625 assert(!KnownValid && "unhandled case in overloaded call candidate");
12626}
12627
12628/// Add the overload candidates named by callee and/or found by argument
12629/// dependent lookup to the given overload set.
12630void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
12631 ArrayRef<Expr *> Args,
12632 OverloadCandidateSet &CandidateSet,
12633 bool PartialOverloading) {
12634
12635#ifndef NDEBUG
12636 // Verify that ArgumentDependentLookup is consistent with the rules
12637 // in C++0x [basic.lookup.argdep]p3:
12638 //
12639 // Let X be the lookup set produced by unqualified lookup (3.4.1)
12640 // and let Y be the lookup set produced by argument dependent
12641 // lookup (defined as follows). If X contains
12642 //
12643 // -- a declaration of a class member, or
12644 //
12645 // -- a block-scope function declaration that is not a
12646 // using-declaration, or
12647 //
12648 // -- a declaration that is neither a function or a function
12649 // template
12650 //
12651 // then Y is empty.
12652
12653 if (ULE->requiresADL()) {
12654 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
12655 E = ULE->decls_end(); I != E; ++I) {
12656 assert(!(*I)->getDeclContext()->isRecord());
12657 assert(isa<UsingShadowDecl>(*I) ||
12658 !(*I)->getDeclContext()->isFunctionOrMethod());
12659 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
12660 }
12661 }
12662#endif
12663
12664 // It would be nice to avoid this copy.
12665 TemplateArgumentListInfo TABuffer;
12666 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
12667 if (ULE->hasExplicitTemplateArgs()) {
12668 ULE->copyTemplateArgumentsInto(TABuffer);
12669 ExplicitTemplateArgs = &TABuffer;
12670 }
12671
12672 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
12673 E = ULE->decls_end(); I != E; ++I)
12674 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
12675 CandidateSet, PartialOverloading,
12676 /*KnownValid*/ true);
12677
12678 if (ULE->requiresADL())
12679 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
12680 Args, ExplicitTemplateArgs,
12681 CandidateSet, PartialOverloading);
12682}
12683
12684/// Add the call candidates from the given set of lookup results to the given
12685/// overload set. Non-function lookup results are ignored.
12686void Sema::AddOverloadedCallCandidates(
12687 LookupResult &R, TemplateArgumentListInfo *ExplicitTemplateArgs,
12688 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet) {
12689 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
12690 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
12691 CandidateSet, false, /*KnownValid*/ false);
12692}
12693
12694/// Determine whether a declaration with the specified name could be moved into
12695/// a different namespace.
12696static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
12697 switch (Name.getCXXOverloadedOperator()) {
12698 case OO_New: case OO_Array_New:
12699 case OO_Delete: case OO_Array_Delete:
12700 return false;
12701
12702 default:
12703 return true;
12704 }
12705}
12706
12707/// Attempt to recover from an ill-formed use of a non-dependent name in a
12708/// template, where the non-dependent name was declared after the template
12709/// was defined. This is common in code written for a compilers which do not
12710/// correctly implement two-stage name lookup.
12711///
12712/// Returns true if a viable candidate was found and a diagnostic was issued.
12713static bool DiagnoseTwoPhaseLookup(
12714 Sema &SemaRef, SourceLocation FnLoc, const CXXScopeSpec &SS,
12715 LookupResult &R, OverloadCandidateSet::CandidateSetKind CSK,
12716 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
12717 CXXRecordDecl **FoundInClass = nullptr) {
12718 if (!SemaRef.inTemplateInstantiation() || !SS.isEmpty())
12719 return false;
12720
12721 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
12722 if (DC->isTransparentContext())
12723 continue;
12724
12725 SemaRef.LookupQualifiedName(R, DC);
12726
12727 if (!R.empty()) {
12728 R.suppressDiagnostics();
12729
12730 OverloadCandidateSet Candidates(FnLoc, CSK);
12731 SemaRef.AddOverloadedCallCandidates(R, ExplicitTemplateArgs, Args,
12732 Candidates);
12733
12734 OverloadCandidateSet::iterator Best;
12735 OverloadingResult OR =
12736 Candidates.BestViableFunction(SemaRef, FnLoc, Best);
12737
12738 if (auto *RD = dyn_cast<CXXRecordDecl>(DC)) {
12739 // We either found non-function declarations or a best viable function
12740 // at class scope. A class-scope lookup result disables ADL. Don't
12741 // look past this, but let the caller know that we found something that
12742 // either is, or might be, usable in this class.
12743 if (FoundInClass) {
12744 *FoundInClass = RD;
12745 if (OR == OR_Success) {
12746 R.clear();
12747 R.addDecl(Best->FoundDecl.getDecl(), Best->FoundDecl.getAccess());
12748 R.resolveKind();
12749 }
12750 }
12751 return false;
12752 }
12753
12754 if (OR != OR_Success) {
12755 // There wasn't a unique best function or function template.
12756 return false;
12757 }
12758
12759 // Find the namespaces where ADL would have looked, and suggest
12760 // declaring the function there instead.
12761 Sema::AssociatedNamespaceSet AssociatedNamespaces;
12762 Sema::AssociatedClassSet AssociatedClasses;
12763 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
12764 AssociatedNamespaces,
12765 AssociatedClasses);
12766 Sema::AssociatedNamespaceSet SuggestedNamespaces;
12767 if (canBeDeclaredInNamespace(R.getLookupName())) {
12768 DeclContext *Std = SemaRef.getStdNamespace();
12769 for (Sema::AssociatedNamespaceSet::iterator
12770 it = AssociatedNamespaces.begin(),
12771 end = AssociatedNamespaces.end(); it != end; ++it) {
12772 // Never suggest declaring a function within namespace 'std'.
12773 if (Std && Std->Encloses(*it))
12774 continue;
12775
12776 // Never suggest declaring a function within a namespace with a
12777 // reserved name, like __gnu_cxx.
12778 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
12779 if (NS &&
12780 NS->getQualifiedNameAsString().find("__") != std::string::npos)
12781 continue;
12782
12783 SuggestedNamespaces.insert(*it);
12784 }
12785 }
12786
12787 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
12788 << R.getLookupName();
12789 if (SuggestedNamespaces.empty()) {
12790 SemaRef.Diag(Best->Function->getLocation(),
12791 diag::note_not_found_by_two_phase_lookup)
12792 << R.getLookupName() << 0;
12793 } else if (SuggestedNamespaces.size() == 1) {
12794 SemaRef.Diag(Best->Function->getLocation(),
12795 diag::note_not_found_by_two_phase_lookup)
12796 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
12797 } else {
12798 // FIXME: It would be useful to list the associated namespaces here,
12799 // but the diagnostics infrastructure doesn't provide a way to produce
12800 // a localized representation of a list of items.
12801 SemaRef.Diag(Best->Function->getLocation(),
12802 diag::note_not_found_by_two_phase_lookup)
12803 << R.getLookupName() << 2;
12804 }
12805
12806 // Try to recover by calling this function.
12807 return true;
12808 }
12809
12810 R.clear();
12811 }
12812
12813 return false;
12814}
12815
12816/// Attempt to recover from ill-formed use of a non-dependent operator in a
12817/// template, where the non-dependent operator was declared after the template
12818/// was defined.
12819///
12820/// Returns true if a viable candidate was found and a diagnostic was issued.
12821static bool
12822DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
12823 SourceLocation OpLoc,
12824 ArrayRef<Expr *> Args) {
12825 DeclarationName OpName =
12826 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
12827 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
12828 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
12829 OverloadCandidateSet::CSK_Operator,
12830 /*ExplicitTemplateArgs=*/nullptr, Args);
12831}
12832
12833namespace {
12834class BuildRecoveryCallExprRAII {
12835 Sema &SemaRef;
12836public:
12837 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
12838 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
12839 SemaRef.IsBuildingRecoveryCallExpr = true;
12840 }
12841
12842 ~BuildRecoveryCallExprRAII() {
12843 SemaRef.IsBuildingRecoveryCallExpr = false;
12844 }
12845};
12846
12847}
12848
12849/// Attempts to recover from a call where no functions were found.
12850///
12851/// This function will do one of three things:
12852/// * Diagnose, recover, and return a recovery expression.
12853/// * Diagnose, fail to recover, and return ExprError().
12854/// * Do not diagnose, do not recover, and return ExprResult(). The caller is
12855/// expected to diagnose as appropriate.
12856static ExprResult
12857BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
12858 UnresolvedLookupExpr *ULE,
12859 SourceLocation LParenLoc,
12860 MutableArrayRef<Expr *> Args,
12861 SourceLocation RParenLoc,
12862 bool EmptyLookup, bool AllowTypoCorrection) {
12863 // Do not try to recover if it is already building a recovery call.
12864 // This stops infinite loops for template instantiations like
12865 //
12866 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
12867 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
12868 if (SemaRef.IsBuildingRecoveryCallExpr)
12869 return ExprResult();
12870 BuildRecoveryCallExprRAII RCE(SemaRef);
12871
12872 CXXScopeSpec SS;
12873 SS.Adopt(ULE->getQualifierLoc());
12874 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
12875
12876 TemplateArgumentListInfo TABuffer;
12877 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
12878 if (ULE->hasExplicitTemplateArgs()) {
12879 ULE->copyTemplateArgumentsInto(TABuffer);
12880 ExplicitTemplateArgs = &TABuffer;
12881 }
12882
12883 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
12884 Sema::LookupOrdinaryName);
12885 CXXRecordDecl *FoundInClass = nullptr;
12886 if (DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
12887 OverloadCandidateSet::CSK_Normal,
12888 ExplicitTemplateArgs, Args, &FoundInClass)) {
12889 // OK, diagnosed a two-phase lookup issue.
12890 } else if (EmptyLookup) {
12891 // Try to recover from an empty lookup with typo correction.
12892 R.clear();
12893 NoTypoCorrectionCCC NoTypoValidator{};
12894 FunctionCallFilterCCC FunctionCallValidator(SemaRef, Args.size(),
12895 ExplicitTemplateArgs != nullptr,
12896 dyn_cast<MemberExpr>(Fn));
12897 CorrectionCandidateCallback &Validator =
12898 AllowTypoCorrection
12899 ? static_cast<CorrectionCandidateCallback &>(FunctionCallValidator)
12900 : static_cast<CorrectionCandidateCallback &>(NoTypoValidator);
12901 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Validator, ExplicitTemplateArgs,
12902 Args))
12903 return ExprError();
12904 } else if (FoundInClass && SemaRef.getLangOpts().MSVCCompat) {
12905 // We found a usable declaration of the name in a dependent base of some
12906 // enclosing class.
12907 // FIXME: We should also explain why the candidates found by name lookup
12908 // were not viable.
12909 if (SemaRef.DiagnoseDependentMemberLookup(R))
12910 return ExprError();
12911 } else {
12912 // We had viable candidates and couldn't recover; let the caller diagnose
12913 // this.
12914 return ExprResult();
12915 }
12916
12917 // If we get here, we should have issued a diagnostic and formed a recovery
12918 // lookup result.
12919 assert(!R.empty() && "lookup results empty despite recovery");
12920
12921 // If recovery created an ambiguity, just bail out.
12922 if (R.isAmbiguous()) {
12923 R.suppressDiagnostics();
12924 return ExprError();
12925 }
12926
12927 // Build an implicit member call if appropriate. Just drop the
12928 // casts and such from the call, we don't really care.
12929 ExprResult NewFn = ExprError();
12930 if ((*R.begin())->isCXXClassMember())
12931 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
12932 ExplicitTemplateArgs, S);
12933 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
12934 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
12935 ExplicitTemplateArgs);
12936 else
12937 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
12938
12939 if (NewFn.isInvalid())
12940 return ExprError();
12941
12942 // This shouldn't cause an infinite loop because we're giving it
12943 // an expression with viable lookup results, which should never
12944 // end up here.
12945 return SemaRef.BuildCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
12946 MultiExprArg(Args.data(), Args.size()),
12947 RParenLoc);
12948}
12949
12950/// Constructs and populates an OverloadedCandidateSet from
12951/// the given function.
12952/// \returns true when an the ExprResult output parameter has been set.
12953bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
12954 UnresolvedLookupExpr *ULE,
12955 MultiExprArg Args,
12956 SourceLocation RParenLoc,
12957 OverloadCandidateSet *CandidateSet,
12958 ExprResult *Result) {
12959#ifndef NDEBUG
12960 if (ULE->requiresADL()) {
12961 // To do ADL, we must have found an unqualified name.
12962 assert(!ULE->getQualifier() && "qualified name with ADL");
12963
12964 // We don't perform ADL for implicit declarations of builtins.
12965 // Verify that this was correctly set up.
12966 FunctionDecl *F;
12967 if (ULE->decls_begin() != ULE->decls_end() &&
12968 ULE->decls_begin() + 1 == ULE->decls_end() &&
12969 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
12970 F->getBuiltinID() && F->isImplicit())
12971 llvm_unreachable("performing ADL for builtin");
12972
12973 // We don't perform ADL in C.
12974 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
12975 }
12976#endif
12977
12978 UnbridgedCastsSet UnbridgedCasts;
12979 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
12980 *Result = ExprError();
12981 return true;
12982 }
12983
12984 // Add the functions denoted by the callee to the set of candidate
12985 // functions, including those from argument-dependent lookup.
12986 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
12987
12988 if (getLangOpts().MSVCCompat &&
12989 CurContext->isDependentContext() && !isSFINAEContext() &&
12990 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
12991
12992 OverloadCandidateSet::iterator Best;
12993 if (CandidateSet->empty() ||
12994 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best) ==
12995 OR_No_Viable_Function) {
12996 // In Microsoft mode, if we are inside a template class member function
12997 // then create a type dependent CallExpr. The goal is to postpone name
12998 // lookup to instantiation time to be able to search into type dependent
12999 // base classes.
13000 CallExpr *CE =
13001 CallExpr::Create(Context, Fn, Args, Context.DependentTy, VK_RValue,
13002 RParenLoc, CurFPFeatureOverrides());
13003 CE->markDependentForPostponedNameLookup();
13004 *Result = CE;
13005 return true;
13006 }
13007 }
13008
13009 if (CandidateSet->empty())
13010 return false;
13011
13012 UnbridgedCasts.restore();
13013 return false;
13014}
13015
13016// Guess at what the return type for an unresolvable overload should be.
13017static QualType chooseRecoveryType(OverloadCandidateSet &CS,
13018 OverloadCandidateSet::iterator *Best) {
13019 llvm::Optional<QualType> Result;
13020 // Adjust Type after seeing a candidate.
13021 auto ConsiderCandidate = [&](const OverloadCandidate &Candidate) {
13022 if (!Candidate.Function)
13023 return;
13024 if (Candidate.Function->isInvalidDecl())
13025 return;
13026 QualType T = Candidate.Function->getReturnType();
13027 if (T.isNull())
13028 return;
13029 if (!Result)
13030 Result = T;
13031 else if (Result != T)
13032 Result = QualType();
13033 };
13034
13035 // Look for an unambiguous type from a progressively larger subset.
13036 // e.g. if types disagree, but all *viable* overloads return int, choose int.
13037 //
13038 // First, consider only the best candidate.
13039 if (Best && *Best != CS.end())
13040 ConsiderCandidate(**Best);
13041 // Next, consider only viable candidates.
13042 if (!Result)
13043 for (const auto &C : CS)
13044 if (C.Viable)
13045 ConsiderCandidate(C);
13046 // Finally, consider all candidates.
13047 if (!Result)
13048 for (const auto &C : CS)
13049 ConsiderCandidate(C);
13050
13051 if (!Result)
13052 return QualType();
13053 auto Value = Result.getValue();
13054 if (Value.isNull() || Value->isUndeducedType())
13055 return QualType();
13056 return Value;
13057}
13058
13059/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
13060/// the completed call expression. If overload resolution fails, emits
13061/// diagnostics and returns ExprError()
13062static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
13063 UnresolvedLookupExpr *ULE,
13064 SourceLocation LParenLoc,
13065 MultiExprArg Args,
13066 SourceLocation RParenLoc,
13067 Expr *ExecConfig,
13068 OverloadCandidateSet *CandidateSet,
13069 OverloadCandidateSet::iterator *Best,
13070 OverloadingResult OverloadResult,
13071 bool AllowTypoCorrection) {
13072 switch (OverloadResult) {
13073 case OR_Success: {
13074 FunctionDecl *FDecl = (*Best)->Function;
13075 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
13076 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
13077 return ExprError();
13078 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
13079 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
13080 ExecConfig, /*IsExecConfig=*/false,
13081 (*Best)->IsADLCandidate);
13082 }
13083
13084 case OR_No_Viable_Function: {
13085 // Try to recover by looking for viable functions which the user might
13086 // have meant to call.
13087 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
13088 Args, RParenLoc,
13089 CandidateSet->empty(),
13090 AllowTypoCorrection);
13091 if (Recovery.isInvalid() || Recovery.isUsable())
13092 return Recovery;
13093
13094 // If the user passes in a function that we can't take the address of, we
13095 // generally end up emitting really bad error messages. Here, we attempt to
13096 // emit better ones.
13097 for (const Expr *Arg : Args) {
13098 if (!Arg->getType()->isFunctionType())
13099 continue;
13100 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
13101 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
13102 if (FD &&
13103 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
13104 Arg->getExprLoc()))
13105 return ExprError();
13106 }
13107 }
13108
13109 CandidateSet->NoteCandidates(
13110 PartialDiagnosticAt(
13111 Fn->getBeginLoc(),
13112 SemaRef.PDiag(diag::err_ovl_no_viable_function_in_call)
13113 << ULE->getName() << Fn->getSourceRange()),
13114 SemaRef, OCD_AllCandidates, Args);
13115 break;
13116 }
13117
13118 case OR_Ambiguous:
13119 CandidateSet->NoteCandidates(
13120 PartialDiagnosticAt(Fn->getBeginLoc(),
13121 SemaRef.PDiag(diag::err_ovl_ambiguous_call)
13122 << ULE->getName() << Fn->getSourceRange()),
13123 SemaRef, OCD_AmbiguousCandidates, Args);
13124 break;
13125
13126 case OR_Deleted: {
13127 CandidateSet->NoteCandidates(
13128 PartialDiagnosticAt(Fn->getBeginLoc(),
13129 SemaRef.PDiag(diag::err_ovl_deleted_call)
13130 << ULE->getName() << Fn->getSourceRange()),
13131 SemaRef, OCD_AllCandidates, Args);
13132
13133 // We emitted an error for the unavailable/deleted function call but keep
13134 // the call in the AST.
13135 FunctionDecl *FDecl = (*Best)->Function;
13136 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
13137 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
13138 ExecConfig, /*IsExecConfig=*/false,
13139 (*Best)->IsADLCandidate);
13140 }
13141 }
13142
13143 // Overload resolution failed, try to recover.
13144 SmallVector<Expr *, 8> SubExprs = {Fn};
13145 SubExprs.append(Args.begin(), Args.end());
13146 return SemaRef.CreateRecoveryExpr(Fn->getBeginLoc(), RParenLoc, SubExprs,
13147 chooseRecoveryType(*CandidateSet, Best));
13148}
13149
13150static void markUnaddressableCandidatesUnviable(Sema &S,
13151 OverloadCandidateSet &CS) {
13152 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
13153 if (I->Viable &&
13154 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
13155 I->Viable = false;
13156 I->FailureKind = ovl_fail_addr_not_available;
13157 }
13158 }
13159}
13160
13161/// BuildOverloadedCallExpr - Given the call expression that calls Fn
13162/// (which eventually refers to the declaration Func) and the call
13163/// arguments Args/NumArgs, attempt to resolve the function call down
13164/// to a specific function. If overload resolution succeeds, returns
13165/// the call expression produced by overload resolution.
13166/// Otherwise, emits diagnostics and returns ExprError.
13167ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
13168 UnresolvedLookupExpr *ULE,
13169 SourceLocation LParenLoc,
13170 MultiExprArg Args,
13171 SourceLocation RParenLoc,
13172 Expr *ExecConfig,
13173 bool AllowTypoCorrection,
13174 bool CalleesAddressIsTaken) {
13175 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
13176 OverloadCandidateSet::CSK_Normal);
13177 ExprResult result;
13178
13179 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
13180 &result))
13181 return result;
13182
13183 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
13184 // functions that aren't addressible are considered unviable.
13185 if (CalleesAddressIsTaken)
13186 markUnaddressableCandidatesUnviable(*this, CandidateSet);
13187
13188 OverloadCandidateSet::iterator Best;
13189 OverloadingResult OverloadResult =
13190 CandidateSet.BestViableFunction(*this, Fn->getBeginLoc(), Best);
13191
13192 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, RParenLoc,
13193 ExecConfig, &CandidateSet, &Best,
13194 OverloadResult, AllowTypoCorrection);
13195}
13196
13197static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
13198 return Functions.size() > 1 ||
13199 (Functions.size() == 1 &&
13200 isa<FunctionTemplateDecl>((*Functions.begin())->getUnderlyingDecl()));
13201}
13202
13203ExprResult Sema::CreateUnresolvedLookupExpr(CXXRecordDecl *NamingClass,
13204 NestedNameSpecifierLoc NNSLoc,
13205 DeclarationNameInfo DNI,
13206 const UnresolvedSetImpl &Fns,
13207 bool PerformADL) {
13208 return UnresolvedLookupExpr::Create(Context, NamingClass, NNSLoc, DNI,
13209 PerformADL, IsOverloaded(Fns),
13210 Fns.begin(), Fns.end());
13211}
13212
13213/// Create a unary operation that may resolve to an overloaded
13214/// operator.
13215///
13216/// \param OpLoc The location of the operator itself (e.g., '*').
13217///
13218/// \param Opc The UnaryOperatorKind that describes this operator.
13219///
13220/// \param Fns The set of non-member functions that will be
13221/// considered by overload resolution. The caller needs to build this
13222/// set based on the context using, e.g.,
13223/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
13224/// set should not contain any member functions; those will be added
13225/// by CreateOverloadedUnaryOp().
13226///
13227/// \param Input The input argument.
13228ExprResult
13229Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
13230 const UnresolvedSetImpl &Fns,
13231 Expr *Input, bool PerformADL) {
13232 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
13233 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
13234 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
13235 // TODO: provide better source location info.
13236 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
13237
13238 if (checkPlaceholderForOverload(*this, Input))
13239 return ExprError();
13240
13241 Expr *Args[2] = { Input, nullptr };
13242 unsigned NumArgs = 1;
13243
13244 // For post-increment and post-decrement, add the implicit '0' as
13245 // the second argument, so that we know this is a post-increment or
13246 // post-decrement.
13247 if (Opc == UO_PostInc || Opc == UO_PostDec) {
13248 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
13249 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
13250 SourceLocation());
13251 NumArgs = 2;
13252 }
13253
13254 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
13255
13256 if (Input->isTypeDependent()) {
13257 if (Fns.empty())
13258 return UnaryOperator::Create(Context, Input, Opc, Context.DependentTy,
13259 VK_RValue, OK_Ordinary, OpLoc, false,
13260 CurFPFeatureOverrides());
13261
13262 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
13263 ExprResult Fn = CreateUnresolvedLookupExpr(
13264 NamingClass, NestedNameSpecifierLoc(), OpNameInfo, Fns);
13265 if (Fn.isInvalid())
13266 return ExprError();
13267 return CXXOperatorCallExpr::Create(Context, Op, Fn.get(), ArgsArray,
13268 Context.DependentTy, VK_RValue, OpLoc,
13269 CurFPFeatureOverrides());
13270 }
13271
13272 // Build an empty overload set.
13273 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
13274
13275 // Add the candidates from the given function set.
13276 AddNonMemberOperatorCandidates(Fns, ArgsArray, CandidateSet);
13277
13278 // Add operator candidates that are member functions.
13279 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
13280
13281 // Add candidates from ADL.
13282 if (PerformADL) {
13283 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
13284 /*ExplicitTemplateArgs*/nullptr,
13285 CandidateSet);
13286 }
13287
13288 // Add builtin operator candidates.
13289 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
13290
13291 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13292
13293 // Perform overload resolution.
13294 OverloadCandidateSet::iterator Best;
13295 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13296 case OR_Success: {
13297 // We found a built-in operator or an overloaded operator.
13298 FunctionDecl *FnDecl = Best->Function;
13299
13300 if (FnDecl) {
13301 Expr *Base = nullptr;
13302 // We matched an overloaded operator. Build a call to that
13303 // operator.
13304
13305 // Convert the arguments.
13306 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
13307 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
13308
13309 ExprResult InputRes =
13310 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
13311 Best->FoundDecl, Method);
13312 if (InputRes.isInvalid())
13313 return ExprError();
13314 Base = Input = InputRes.get();
13315 } else {
13316 // Convert the arguments.
13317 ExprResult InputInit
13318 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
13319 Context,
13320 FnDecl->getParamDecl(0)),
13321 SourceLocation(),
13322 Input);
13323 if (InputInit.isInvalid())
13324 return ExprError();
13325 Input = InputInit.get();
13326 }
13327
13328 // Build the actual expression node.
13329 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
13330 Base, HadMultipleCandidates,
13331 OpLoc);
13332 if (FnExpr.isInvalid())
13333 return ExprError();
13334
13335 // Determine the result type.
13336 QualType ResultTy = FnDecl->getReturnType();
13337 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13338 ResultTy = ResultTy.getNonLValueExprType(Context);
13339
13340 Args[0] = Input;
13341 CallExpr *TheCall = CXXOperatorCallExpr::Create(
13342 Context, Op, FnExpr.get(), ArgsArray, ResultTy, VK, OpLoc,
13343 CurFPFeatureOverrides(), Best->IsADLCandidate);
13344
13345 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
13346 return ExprError();
13347
13348 if (CheckFunctionCall(FnDecl, TheCall,
13349 FnDecl->getType()->castAs<FunctionProtoType>()))
13350 return ExprError();
13351 return CheckForImmediateInvocation(MaybeBindToTemporary(TheCall), FnDecl);
13352 } else {
13353 // We matched a built-in operator. Convert the arguments, then
13354 // break out so that we will build the appropriate built-in
13355 // operator node.
13356 ExprResult InputRes = PerformImplicitConversion(
13357 Input, Best->BuiltinParamTypes[0], Best->Conversions[0], AA_Passing,
13358 CCK_ForBuiltinOverloadedOp);
13359 if (InputRes.isInvalid())
13360 return ExprError();
13361 Input = InputRes.get();
13362 break;
13363 }
13364 }
13365
13366 case OR_No_Viable_Function:
13367 // This is an erroneous use of an operator which can be overloaded by
13368 // a non-member function. Check for non-member operators which were
13369 // defined too late to be candidates.
13370 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
13371 // FIXME: Recover by calling the found function.
13372 return ExprError();
13373
13374 // No viable function; fall through to handling this as a
13375 // built-in operator, which will produce an error message for us.
13376 break;
13377
13378 case OR_Ambiguous:
13379 CandidateSet.NoteCandidates(
13380 PartialDiagnosticAt(OpLoc,
13381 PDiag(diag::err_ovl_ambiguous_oper_unary)
13382 << UnaryOperator::getOpcodeStr(Opc)
13383 << Input->getType() << Input->getSourceRange()),
13384 *this, OCD_AmbiguousCandidates, ArgsArray,
13385 UnaryOperator::getOpcodeStr(Opc), OpLoc);
13386 return ExprError();
13387
13388 case OR_Deleted:
13389 CandidateSet.NoteCandidates(
13390 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
13391 << UnaryOperator::getOpcodeStr(Opc)
13392 << Input->getSourceRange()),
13393 *this, OCD_AllCandidates, ArgsArray, UnaryOperator::getOpcodeStr(Opc),
13394 OpLoc);
13395 return ExprError();
13396 }
13397
13398 // Either we found no viable overloaded operator or we matched a
13399 // built-in operator. In either case, fall through to trying to
13400 // build a built-in operation.
13401 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
13402}
13403
13404/// Perform lookup for an overloaded binary operator.
13405void Sema::LookupOverloadedBinOp(OverloadCandidateSet &CandidateSet,
13406 OverloadedOperatorKind Op,
13407 const UnresolvedSetImpl &Fns,
13408 ArrayRef<Expr *> Args, bool PerformADL) {
13409 SourceLocation OpLoc = CandidateSet.getLocation();
13410
13411 OverloadedOperatorKind ExtraOp =
13412 CandidateSet.getRewriteInfo().AllowRewrittenCandidates
13413 ? getRewrittenOverloadedOperator(Op)
13414 : OO_None;
13415
13416 // Add the candidates from the given function set. This also adds the
13417 // rewritten candidates using these functions if necessary.
13418 AddNonMemberOperatorCandidates(Fns, Args, CandidateSet);
13419
13420 // Add operator candidates that are member functions.
13421 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
13422 if (CandidateSet.getRewriteInfo().shouldAddReversed(Op))
13423 AddMemberOperatorCandidates(Op, OpLoc, {Args[1], Args[0]}, CandidateSet,
13424 OverloadCandidateParamOrder::Reversed);
13425
13426 // In C++20, also add any rewritten member candidates.
13427 if (ExtraOp) {
13428 AddMemberOperatorCandidates(ExtraOp, OpLoc, Args, CandidateSet);
13429 if (CandidateSet.getRewriteInfo().shouldAddReversed(ExtraOp))
13430 AddMemberOperatorCandidates(ExtraOp, OpLoc, {Args[1], Args[0]},
13431 CandidateSet,
13432 OverloadCandidateParamOrder::Reversed);
13433 }
13434
13435 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
13436 // performed for an assignment operator (nor for operator[] nor operator->,
13437 // which don't get here).
13438 if (Op != OO_Equal && PerformADL) {
13439 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
13440 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
13441 /*ExplicitTemplateArgs*/ nullptr,
13442 CandidateSet);
13443 if (ExtraOp) {
13444 DeclarationName ExtraOpName =
13445 Context.DeclarationNames.getCXXOperatorName(ExtraOp);
13446 AddArgumentDependentLookupCandidates(ExtraOpName, OpLoc, Args,
13447 /*ExplicitTemplateArgs*/ nullptr,
13448 CandidateSet);
13449 }
13450 }
13451
13452 // Add builtin operator candidates.
13453 //
13454 // FIXME: We don't add any rewritten candidates here. This is strictly
13455 // incorrect; a builtin candidate could be hidden by a non-viable candidate,
13456 // resulting in our selecting a rewritten builtin candidate. For example:
13457 //
13458 // enum class E { e };
13459 // bool operator!=(E, E) requires false;
13460 // bool k = E::e != E::e;
13461 //
13462 // ... should select the rewritten builtin candidate 'operator==(E, E)'. But
13463 // it seems unreasonable to consider rewritten builtin candidates. A core
13464 // issue has been filed proposing to removed this requirement.
13465 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
13466}
13467
13468/// Create a binary operation that may resolve to an overloaded
13469/// operator.
13470///
13471/// \param OpLoc The location of the operator itself (e.g., '+').
13472///
13473/// \param Opc The BinaryOperatorKind that describes this operator.
13474///
13475/// \param Fns The set of non-member functions that will be
13476/// considered by overload resolution. The caller needs to build this
13477/// set based on the context using, e.g.,
13478/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
13479/// set should not contain any member functions; those will be added
13480/// by CreateOverloadedBinOp().
13481///
13482/// \param LHS Left-hand argument.
13483/// \param RHS Right-hand argument.
13484/// \param PerformADL Whether to consider operator candidates found by ADL.
13485/// \param AllowRewrittenCandidates Whether to consider candidates found by
13486/// C++20 operator rewrites.
13487/// \param DefaultedFn If we are synthesizing a defaulted operator function,
13488/// the function in question. Such a function is never a candidate in
13489/// our overload resolution. This also enables synthesizing a three-way
13490/// comparison from < and == as described in C++20 [class.spaceship]p1.
13491ExprResult Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
13492 BinaryOperatorKind Opc,
13493 const UnresolvedSetImpl &Fns, Expr *LHS,
13494 Expr *RHS, bool PerformADL,
13495 bool AllowRewrittenCandidates,
13496 FunctionDecl *DefaultedFn) {
13497 Expr *Args[2] = { LHS, RHS };
13498 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
13499
13500 if (!getLangOpts().CPlusPlus20)
13501 AllowRewrittenCandidates = false;
13502
13503 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
13504
13505 // If either side is type-dependent, create an appropriate dependent
13506 // expression.
13507 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
13508 if (Fns.empty()) {
13509 // If there are no functions to store, just build a dependent
13510 // BinaryOperator or CompoundAssignment.
13511 if (BinaryOperator::isCompoundAssignmentOp(Opc))
13512 return CompoundAssignOperator::Create(
13513 Context, Args[0], Args[1], Opc, Context.DependentTy, VK_LValue,
13514 OK_Ordinary, OpLoc, CurFPFeatureOverrides(), Context.DependentTy,
13515 Context.DependentTy);
13516 return BinaryOperator::Create(Context, Args[0], Args[1], Opc,
13517 Context.DependentTy, VK_RValue, OK_Ordinary,
13518 OpLoc, CurFPFeatureOverrides());
13519 }
13520
13521 // FIXME: save results of ADL from here?
13522 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
13523 // TODO: provide better source location info in DNLoc component.
13524 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
13525 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
13526 ExprResult Fn = CreateUnresolvedLookupExpr(
13527 NamingClass, NestedNameSpecifierLoc(), OpNameInfo, Fns, PerformADL);
13528 if (Fn.isInvalid())
13529 return ExprError();
13530 return CXXOperatorCallExpr::Create(Context, Op, Fn.get(), Args,
13531 Context.DependentTy, VK_RValue, OpLoc,
13532 CurFPFeatureOverrides());
13533 }
13534
13535 // Always do placeholder-like conversions on the RHS.
13536 if (checkPlaceholderForOverload(*this, Args[1]))
13537 return ExprError();
13538
13539 // Do placeholder-like conversion on the LHS; note that we should
13540 // not get here with a PseudoObject LHS.
13541 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
13542 if (checkPlaceholderForOverload(*this, Args[0]))
13543 return ExprError();
13544
13545 // If this is the assignment operator, we only perform overload resolution
13546 // if the left-hand side is a class or enumeration type. This is actually
13547 // a hack. The standard requires that we do overload resolution between the
13548 // various built-in candidates, but as DR507 points out, this can lead to
13549 // problems. So we do it this way, which pretty much follows what GCC does.
13550 // Note that we go the traditional code path for compound assignment forms.
13551 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
13552 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13553
13554 // If this is the .* operator, which is not overloadable, just
13555 // create a built-in binary operator.
13556 if (Opc == BO_PtrMemD)
13557 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13558
13559 // Build the overload set.
13560 OverloadCandidateSet CandidateSet(
13561 OpLoc, OverloadCandidateSet::CSK_Operator,
13562 OverloadCandidateSet::OperatorRewriteInfo(Op, AllowRewrittenCandidates));
13563 if (DefaultedFn)
13564 CandidateSet.exclude(DefaultedFn);
13565 LookupOverloadedBinOp(CandidateSet, Op, Fns, Args, PerformADL);
13566
13567 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13568
13569 // Perform overload resolution.
13570 OverloadCandidateSet::iterator Best;
13571 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13572 case OR_Success: {
13573 // We found a built-in operator or an overloaded operator.
13574 FunctionDecl *FnDecl = Best->Function;
13575
13576 bool IsReversed = Best->isReversed();
13577 if (IsReversed)
13578 std::swap(Args[0], Args[1]);
13579
13580 if (FnDecl) {
13581 Expr *Base = nullptr;
13582 // We matched an overloaded operator. Build a call to that
13583 // operator.
13584
13585 OverloadedOperatorKind ChosenOp =
13586 FnDecl->getDeclName().getCXXOverloadedOperator();
13587
13588 // C++2a [over.match.oper]p9:
13589 // If a rewritten operator== candidate is selected by overload
13590 // resolution for an operator@, its return type shall be cv bool
13591 if (Best->RewriteKind && ChosenOp == OO_EqualEqual &&
13592 !FnDecl->getReturnType()->isBooleanType()) {
13593 bool IsExtension =
13594 FnDecl->getReturnType()->isIntegralOrUnscopedEnumerationType();
13595 Diag(OpLoc, IsExtension ? diag::ext_ovl_rewrite_equalequal_not_bool
13596 : diag::err_ovl_rewrite_equalequal_not_bool)
13597 << FnDecl->getReturnType() << BinaryOperator::getOpcodeStr(Opc)
13598 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13599 Diag(FnDecl->getLocation(), diag::note_declared_at);
13600 if (!IsExtension)
13601 return ExprError();
13602 }
13603
13604 if (AllowRewrittenCandidates && !IsReversed &&
13605 CandidateSet.getRewriteInfo().isReversible()) {
13606 // We could have reversed this operator, but didn't. Check if some
13607 // reversed form was a viable candidate, and if so, if it had a
13608 // better conversion for either parameter. If so, this call is
13609 // formally ambiguous, and allowing it is an extension.
13610 llvm::SmallVector<FunctionDecl*, 4> AmbiguousWith;
13611 for (OverloadCandidate &Cand : CandidateSet) {
13612 if (Cand.Viable && Cand.Function && Cand.isReversed() &&
13613 haveSameParameterTypes(Context, Cand.Function, FnDecl, 2)) {
13614 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
13615 if (CompareImplicitConversionSequences(
13616 *this, OpLoc, Cand.Conversions[ArgIdx],
13617 Best->Conversions[ArgIdx]) ==
13618 ImplicitConversionSequence::Better) {
13619 AmbiguousWith.push_back(Cand.Function);
13620 break;
13621 }
13622 }
13623 }
13624 }
13625
13626 if (!AmbiguousWith.empty()) {
13627 bool AmbiguousWithSelf =
13628 AmbiguousWith.size() == 1 &&
13629 declaresSameEntity(AmbiguousWith.front(), FnDecl);
13630 Diag(OpLoc, diag::ext_ovl_ambiguous_oper_binary_reversed)
13631 << BinaryOperator::getOpcodeStr(Opc)
13632 << Args[0]->getType() << Args[1]->getType() << AmbiguousWithSelf
13633 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13634 if (AmbiguousWithSelf) {
13635 Diag(FnDecl->getLocation(),
13636 diag::note_ovl_ambiguous_oper_binary_reversed_self);
13637 } else {
13638 Diag(FnDecl->getLocation(),
13639 diag::note_ovl_ambiguous_oper_binary_selected_candidate);
13640 for (auto *F : AmbiguousWith)
13641 Diag(F->getLocation(),
13642 diag::note_ovl_ambiguous_oper_binary_reversed_candidate);
13643 }
13644 }
13645 }
13646
13647 // Convert the arguments.
13648 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
13649 // Best->Access is only meaningful for class members.
13650 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
13651
13652 ExprResult Arg1 =
13653 PerformCopyInitialization(
13654 InitializedEntity::InitializeParameter(Context,
13655 FnDecl->getParamDecl(0)),
13656 SourceLocation(), Args[1]);
13657 if (Arg1.isInvalid())
13658 return ExprError();
13659
13660 ExprResult Arg0 =
13661 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
13662 Best->FoundDecl, Method);
13663 if (Arg0.isInvalid())
13664 return ExprError();
13665 Base = Args[0] = Arg0.getAs<Expr>();
13666 Args[1] = RHS = Arg1.getAs<Expr>();
13667 } else {
13668 // Convert the arguments.
13669 ExprResult Arg0 = PerformCopyInitialization(
13670 InitializedEntity::InitializeParameter(Context,
13671 FnDecl->getParamDecl(0)),
13672 SourceLocation(), Args[0]);
13673 if (Arg0.isInvalid())
13674 return ExprError();
13675
13676 ExprResult Arg1 =
13677 PerformCopyInitialization(
13678 InitializedEntity::InitializeParameter(Context,
13679 FnDecl->getParamDecl(1)),
13680 SourceLocation(), Args[1]);
13681 if (Arg1.isInvalid())
13682 return ExprError();
13683 Args[0] = LHS = Arg0.getAs<Expr>();
13684 Args[1] = RHS = Arg1.getAs<Expr>();
13685 }
13686
13687 // Build the actual expression node.
13688 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
13689 Best->FoundDecl, Base,
13690 HadMultipleCandidates, OpLoc);
13691 if (FnExpr.isInvalid())
13692 return ExprError();
13693
13694 // Determine the result type.
13695 QualType ResultTy = FnDecl->getReturnType();
13696 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13697 ResultTy = ResultTy.getNonLValueExprType(Context);
13698
13699 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
13700 Context, ChosenOp, FnExpr.get(), Args, ResultTy, VK, OpLoc,
13701 CurFPFeatureOverrides(), Best->IsADLCandidate);
13702
13703 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
13704 FnDecl))
13705 return ExprError();
13706
13707 ArrayRef<const Expr *> ArgsArray(Args, 2);
13708 const Expr *ImplicitThis = nullptr;
13709 // Cut off the implicit 'this'.
13710 if (isa<CXXMethodDecl>(FnDecl)) {
13711 ImplicitThis = ArgsArray[0];
13712 ArgsArray = ArgsArray.slice(1);
13713 }
13714
13715 // Check for a self move.
13716 if (Op == OO_Equal)
13717 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
13718
13719 checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
13720 isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
13721 VariadicDoesNotApply);
13722
13723 ExprResult R = MaybeBindToTemporary(TheCall);
13724 if (R.isInvalid())
13725 return ExprError();
13726
13727 R = CheckForImmediateInvocation(R, FnDecl);
13728 if (R.isInvalid())
13729 return ExprError();
13730
13731 // For a rewritten candidate, we've already reversed the arguments
13732 // if needed. Perform the rest of the rewrite now.
13733 if ((Best->RewriteKind & CRK_DifferentOperator) ||
13734 (Op == OO_Spaceship && IsReversed)) {
13735 if (Op == OO_ExclaimEqual) {
13736 assert(ChosenOp == OO_EqualEqual && "unexpected operator name");
13737 R = CreateBuiltinUnaryOp(OpLoc, UO_LNot, R.get());
13738 } else {
13739 assert(ChosenOp == OO_Spaceship && "unexpected operator name");
13740 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
13741 Expr *ZeroLiteral =
13742 IntegerLiteral::Create(Context, Zero, Context.IntTy, OpLoc);
13743
13744 Sema::CodeSynthesisContext Ctx;
13745 Ctx.Kind = Sema::CodeSynthesisContext::RewritingOperatorAsSpaceship;
13746 Ctx.Entity = FnDecl;
13747 pushCodeSynthesisContext(Ctx);
13748
13749 R = CreateOverloadedBinOp(
13750 OpLoc, Opc, Fns, IsReversed ? ZeroLiteral : R.get(),
13751 IsReversed ? R.get() : ZeroLiteral, PerformADL,
13752 /*AllowRewrittenCandidates=*/false);
13753
13754 popCodeSynthesisContext();
13755 }
13756 if (R.isInvalid())
13757 return ExprError();
13758 } else {
13759 assert(ChosenOp == Op && "unexpected operator name");
13760 }
13761
13762 // Make a note in the AST if we did any rewriting.
13763 if (Best->RewriteKind != CRK_None)
13764 R = new (Context) CXXRewrittenBinaryOperator(R.get(), IsReversed);
13765
13766 return R;
13767 } else {
13768 // We matched a built-in operator. Convert the arguments, then
13769 // break out so that we will build the appropriate built-in
13770 // operator node.
13771 ExprResult ArgsRes0 = PerformImplicitConversion(
13772 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
13773 AA_Passing, CCK_ForBuiltinOverloadedOp);
13774 if (ArgsRes0.isInvalid())
13775 return ExprError();
13776 Args[0] = ArgsRes0.get();
13777
13778 ExprResult ArgsRes1 = PerformImplicitConversion(
13779 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
13780 AA_Passing, CCK_ForBuiltinOverloadedOp);
13781 if (ArgsRes1.isInvalid())
13782 return ExprError();
13783 Args[1] = ArgsRes1.get();
13784 break;
13785 }
13786 }
13787
13788 case OR_No_Viable_Function: {
13789 // C++ [over.match.oper]p9:
13790 // If the operator is the operator , [...] and there are no
13791 // viable functions, then the operator is assumed to be the
13792 // built-in operator and interpreted according to clause 5.
13793 if (Opc == BO_Comma)
13794 break;
13795
13796 // When defaulting an 'operator<=>', we can try to synthesize a three-way
13797 // compare result using '==' and '<'.
13798 if (DefaultedFn && Opc == BO_Cmp) {
13799 ExprResult E = BuildSynthesizedThreeWayComparison(OpLoc, Fns, Args[0],
13800 Args[1], DefaultedFn);
13801 if (E.isInvalid() || E.isUsable())
13802 return E;
13803 }
13804
13805 // For class as left operand for assignment or compound assignment
13806 // operator do not fall through to handling in built-in, but report that
13807 // no overloaded assignment operator found
13808 ExprResult Result = ExprError();
13809 StringRef OpcStr = BinaryOperator::getOpcodeStr(Opc);
13810 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates,
13811 Args, OpLoc);
13812 if (Args[0]->getType()->isRecordType() &&
13813 Opc >= BO_Assign && Opc <= BO_OrAssign) {
13814 Diag(OpLoc, diag::err_ovl_no_viable_oper)
13815 << BinaryOperator::getOpcodeStr(Opc)
13816 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13817 if (Args[0]->getType()->isIncompleteType()) {
13818 Diag(OpLoc, diag::note_assign_lhs_incomplete)
13819 << Args[0]->getType()
13820 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13821 }
13822 } else {
13823 // This is an erroneous use of an operator which can be overloaded by
13824 // a non-member function. Check for non-member operators which were
13825 // defined too late to be candidates.
13826 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
13827 // FIXME: Recover by calling the found function.
13828 return ExprError();
13829
13830 // No viable function; try to create a built-in operation, which will
13831 // produce an error. Then, show the non-viable candidates.
13832 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13833 }
13834 assert(Result.isInvalid() &&
13835 "C++ binary operator overloading is missing candidates!");
13836 CandidateSet.NoteCandidates(*this, Args, Cands, OpcStr, OpLoc);
13837 return Result;
13838 }
13839
13840 case OR_Ambiguous:
13841 CandidateSet.NoteCandidates(
13842 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
13843 << BinaryOperator::getOpcodeStr(Opc)
13844 << Args[0]->getType()
13845 << Args[1]->getType()
13846 << Args[0]->getSourceRange()
13847 << Args[1]->getSourceRange()),
13848 *this, OCD_AmbiguousCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
13849 OpLoc);
13850 return ExprError();
13851
13852 case OR_Deleted:
13853 if (isImplicitlyDeleted(Best->Function)) {
13854 FunctionDecl *DeletedFD = Best->Function;
13855 DefaultedFunctionKind DFK = getDefaultedFunctionKind(DeletedFD);
13856 if (DFK.isSpecialMember()) {
13857 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
13858 << Args[0]->getType() << DFK.asSpecialMember();
13859 } else {
13860 assert(DFK.isComparison());
13861 Diag(OpLoc, diag::err_ovl_deleted_comparison)
13862 << Args[0]->getType() << DeletedFD;
13863 }
13864
13865 // The user probably meant to call this special member. Just
13866 // explain why it's deleted.
13867 NoteDeletedFunction(DeletedFD);
13868 return ExprError();
13869 }
13870 CandidateSet.NoteCandidates(
13871 PartialDiagnosticAt(
13872 OpLoc, PDiag(diag::err_ovl_deleted_oper)
13873 << getOperatorSpelling(Best->Function->getDeclName()
13874 .getCXXOverloadedOperator())
13875 << Args[0]->getSourceRange()
13876 << Args[1]->getSourceRange()),
13877 *this, OCD_AllCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
13878 OpLoc);
13879 return ExprError();
13880 }
13881
13882 // We matched a built-in operator; build it.
13883 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13884}
13885
13886ExprResult Sema::BuildSynthesizedThreeWayComparison(
13887 SourceLocation OpLoc, const UnresolvedSetImpl &Fns, Expr *LHS, Expr *RHS,
13888 FunctionDecl *DefaultedFn) {
13889 const ComparisonCategoryInfo *Info =
13890 Context.CompCategories.lookupInfoForType(DefaultedFn->getReturnType());
13891 // If we're not producing a known comparison category type, we can't
13892 // synthesize a three-way comparison. Let the caller diagnose this.
13893 if (!Info)
13894 return ExprResult((Expr*)nullptr);
13895
13896 // If we ever want to perform this synthesis more generally, we will need to
13897 // apply the temporary materialization conversion to the operands.
13898 assert(LHS->isGLValue() && RHS->isGLValue() &&
13899 "cannot use prvalue expressions more than once");
13900 Expr *OrigLHS = LHS;
13901 Expr *OrigRHS = RHS;
13902
13903 // Replace the LHS and RHS with OpaqueValueExprs; we're going to refer to
13904 // each of them multiple times below.
13905 LHS = new (Context)
13906 OpaqueValueExpr(LHS->getExprLoc(), LHS->getType(), LHS->getValueKind(),
13907 LHS->getObjectKind(), LHS);
13908 RHS = new (Context)
13909 OpaqueValueExpr(RHS->getExprLoc(), RHS->getType(), RHS->getValueKind(),
13910 RHS->getObjectKind(), RHS);
13911
13912 ExprResult Eq = CreateOverloadedBinOp(OpLoc, BO_EQ, Fns, LHS, RHS, true, true,
13913 DefaultedFn);
13914 if (Eq.isInvalid())
13915 return ExprError();
13916
13917 ExprResult Less = CreateOverloadedBinOp(OpLoc, BO_LT, Fns, LHS, RHS, true,
13918 true, DefaultedFn);
13919 if (Less.isInvalid())
13920 return ExprError();
13921
13922 ExprResult Greater;
13923 if (Info->isPartial()) {
13924 Greater = CreateOverloadedBinOp(OpLoc, BO_LT, Fns, RHS, LHS, true, true,
13925 DefaultedFn);
13926 if (Greater.isInvalid())
13927 return ExprError();
13928 }
13929
13930 // Form the list of comparisons we're going to perform.
13931 struct Comparison {
13932 ExprResult Cmp;
13933 ComparisonCategoryResult Result;
13934 } Comparisons[4] =
13935 { {Eq, Info->isStrong() ? ComparisonCategoryResult::Equal
13936 : ComparisonCategoryResult::Equivalent},
13937 {Less, ComparisonCategoryResult::Less},
13938 {Greater, ComparisonCategoryResult::Greater},
13939 {ExprResult(), ComparisonCategoryResult::Unordered},
13940 };
13941
13942 int I = Info->isPartial() ? 3 : 2;
13943
13944 // Combine the comparisons with suitable conditional expressions.
13945 ExprResult Result;
13946 for (; I >= 0; --I) {
13947 // Build a reference to the comparison category constant.
13948 auto *VI = Info->lookupValueInfo(Comparisons[I].Result);
13949 // FIXME: Missing a constant for a comparison category. Diagnose this?
13950 if (!VI)
13951 return ExprResult((Expr*)nullptr);
13952 ExprResult ThisResult =
13953 BuildDeclarationNameExpr(CXXScopeSpec(), DeclarationNameInfo(), VI->VD);
13954 if (ThisResult.isInvalid())
13955 return ExprError();
13956
13957 // Build a conditional unless this is the final case.
13958 if (Result.get()) {
13959 Result = ActOnConditionalOp(OpLoc, OpLoc, Comparisons[I].Cmp.get(),
13960 ThisResult.get(), Result.get());
13961 if (Result.isInvalid())
13962 return ExprError();
13963 } else {
13964 Result = ThisResult;
13965 }
13966 }
13967
13968 // Build a PseudoObjectExpr to model the rewriting of an <=> operator, and to
13969 // bind the OpaqueValueExprs before they're (repeatedly) used.
13970 Expr *SyntacticForm = BinaryOperator::Create(
13971 Context, OrigLHS, OrigRHS, BO_Cmp, Result.get()->getType(),
13972 Result.get()->getValueKind(), Result.get()->getObjectKind(), OpLoc,
13973 CurFPFeatureOverrides());
13974 Expr *SemanticForm[] = {LHS, RHS, Result.get()};
13975 return PseudoObjectExpr::Create(Context, SyntacticForm, SemanticForm, 2);
13976}
13977
13978ExprResult
13979Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
13980 SourceLocation RLoc,
13981 Expr *Base, Expr *Idx) {
13982 Expr *Args[2] = { Base, Idx };
13983 DeclarationName OpName =
13984 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
13985
13986 // If either side is type-dependent, create an appropriate dependent
13987 // expression.
13988 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
13989
13990 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
13991 // CHECKME: no 'operator' keyword?
13992 DeclarationNameInfo OpNameInfo(OpName, LLoc);
13993 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
13994 ExprResult Fn = CreateUnresolvedLookupExpr(
13995 NamingClass, NestedNameSpecifierLoc(), OpNameInfo, UnresolvedSet<0>());
13996 if (Fn.isInvalid())
13997 return ExprError();
13998 // Can't add any actual overloads yet
13999
14000 return CXXOperatorCallExpr::Create(Context, OO_Subscript, Fn.get(), Args,
14001 Context.DependentTy, VK_RValue, RLoc,
14002 CurFPFeatureOverrides());
14003 }
14004
14005 // Handle placeholders on both operands.
14006 if (checkPlaceholderForOverload(*this, Args[0]))
14007 return ExprError();
14008 if (checkPlaceholderForOverload(*this, Args[1]))
14009 return ExprError();
14010
14011 // Build an empty overload set.
14012 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
14013
14014 // Subscript can only be overloaded as a member function.
14015
14016 // Add operator candidates that are member functions.
14017 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
14018
14019 // Add builtin operator candidates.
14020 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
14021
14022 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14023
14024 // Perform overload resolution.
14025 OverloadCandidateSet::iterator Best;
14026 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
14027 case OR_Success: {
14028 // We found a built-in operator or an overloaded operator.
14029 FunctionDecl *FnDecl = Best->Function;
14030
14031 if (FnDecl) {
14032 // We matched an overloaded operator. Build a call to that
14033 // operator.
14034
14035 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
14036
14037 // Convert the arguments.
14038 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
14039 ExprResult Arg0 =
14040 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
14041 Best->FoundDecl, Method);
14042 if (Arg0.isInvalid())
14043 return ExprError();
14044 Args[0] = Arg0.get();
14045
14046 // Convert the arguments.
14047 ExprResult InputInit
14048 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
14049 Context,
14050 FnDecl->getParamDecl(0)),
14051 SourceLocation(),
14052 Args[1]);
14053 if (InputInit.isInvalid())
14054 return ExprError();
14055
14056 Args[1] = InputInit.getAs<Expr>();
14057
14058 // Build the actual expression node.
14059 DeclarationNameInfo OpLocInfo(OpName, LLoc);
14060 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
14061 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
14062 Best->FoundDecl,
14063 Base,
14064 HadMultipleCandidates,
14065 OpLocInfo.getLoc(),
14066 OpLocInfo.getInfo());
14067 if (FnExpr.isInvalid())
14068 return ExprError();
14069
14070 // Determine the result type
14071 QualType ResultTy = FnDecl->getReturnType();
14072 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14073 ResultTy = ResultTy.getNonLValueExprType(Context);
14074
14075 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
14076 Context, OO_Subscript, FnExpr.get(), Args, ResultTy, VK, RLoc,
14077 CurFPFeatureOverrides());
14078 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
14079 return ExprError();
14080
14081 if (CheckFunctionCall(Method, TheCall,
14082 Method->getType()->castAs<FunctionProtoType>()))
14083 return ExprError();
14084
14085 return MaybeBindToTemporary(TheCall);
14086 } else {
14087 // We matched a built-in operator. Convert the arguments, then
14088 // break out so that we will build the appropriate built-in
14089 // operator node.
14090 ExprResult ArgsRes0 = PerformImplicitConversion(
14091 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
14092 AA_Passing, CCK_ForBuiltinOverloadedOp);
14093 if (ArgsRes0.isInvalid())
14094 return ExprError();
14095 Args[0] = ArgsRes0.get();
14096
14097 ExprResult ArgsRes1 = PerformImplicitConversion(
14098 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
14099 AA_Passing, CCK_ForBuiltinOverloadedOp);
14100 if (ArgsRes1.isInvalid())
14101 return ExprError();
14102 Args[1] = ArgsRes1.get();
14103
14104 break;
14105 }
14106 }
14107
14108 case OR_No_Viable_Function: {
14109 PartialDiagnostic PD = CandidateSet.empty()
14110 ? (PDiag(diag::err_ovl_no_oper)
14111 << Args[0]->getType() << /*subscript*/ 0
14112 << Args[0]->getSourceRange() << Args[1]->getSourceRange())
14113 : (PDiag(diag::err_ovl_no_viable_subscript)
14114 << Args[0]->getType() << Args[0]->getSourceRange()
14115 << Args[1]->getSourceRange());
14116 CandidateSet.NoteCandidates(PartialDiagnosticAt(LLoc, PD), *this,
14117 OCD_AllCandidates, Args, "[]", LLoc);
14118 return ExprError();
14119 }
14120
14121 case OR_Ambiguous:
14122 CandidateSet.NoteCandidates(
14123 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
14124 << "[]" << Args[0]->getType()
14125 << Args[1]->getType()
14126 << Args[0]->getSourceRange()
14127 << Args[1]->getSourceRange()),
14128 *this, OCD_AmbiguousCandidates, Args, "[]", LLoc);
14129 return ExprError();
14130
14131 case OR_Deleted:
14132 CandidateSet.NoteCandidates(
14133 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_deleted_oper)
14134 << "[]" << Args[0]->getSourceRange()
14135 << Args[1]->getSourceRange()),
14136 *this, OCD_AllCandidates, Args, "[]", LLoc);
14137 return ExprError();
14138 }
14139
14140 // We matched a built-in operator; build it.
14141 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
14142}
14143
14144/// BuildCallToMemberFunction - Build a call to a member
14145/// function. MemExpr is the expression that refers to the member
14146/// function (and includes the object parameter), Args/NumArgs are the
14147/// arguments to the function call (not including the object
14148/// parameter). The caller needs to validate that the member
14149/// expression refers to a non-static member function or an overloaded
14150/// member function.
14151ExprResult Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
14152 SourceLocation LParenLoc,
14153 MultiExprArg Args,
14154 SourceLocation RParenLoc,
14155 bool AllowRecovery) {
14156 assert(MemExprE->getType() == Context.BoundMemberTy ||
14157 MemExprE->getType() == Context.OverloadTy);
14158
14159 // Dig out the member expression. This holds both the object
14160 // argument and the member function we're referring to.
14161 Expr *NakedMemExpr = MemExprE->IgnoreParens();
14162
14163 // Determine whether this is a call to a pointer-to-member function.
14164 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
14165 assert(op->getType() == Context.BoundMemberTy);
14166 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
14167
14168 QualType fnType =
14169 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
14170
14171 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
14172 QualType resultType = proto->getCallResultType(Context);
14173 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
14174
14175 // Check that the object type isn't more qualified than the
14176 // member function we're calling.
14177 Qualifiers funcQuals = proto->getMethodQuals();
14178
14179 QualType objectType = op->getLHS()->getType();
14180 if (op->getOpcode() == BO_PtrMemI)
14181 objectType = objectType->castAs<PointerType>()->getPointeeType();
14182 Qualifiers objectQuals = objectType.getQualifiers();
14183
14184 Qualifiers difference = objectQuals - funcQuals;
14185 difference.removeObjCGCAttr();
14186 difference.removeAddressSpace();
14187 if (difference) {
14188 std::string qualsString = difference.getAsString();
14189 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
14190 << fnType.getUnqualifiedType()
14191 << qualsString
14192 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
14193 }
14194
14195 CXXMemberCallExpr *call = CXXMemberCallExpr::Create(
14196 Context, MemExprE, Args, resultType, valueKind, RParenLoc,
14197 CurFPFeatureOverrides(), proto->getNumParams());
14198
14199 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getBeginLoc(),
14200 call, nullptr))
14201 return ExprError();
14202
14203 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
14204 return ExprError();
14205
14206 if (CheckOtherCall(call, proto))
14207 return ExprError();
14208
14209 return MaybeBindToTemporary(call);
14210 }
14211
14212 // We only try to build a recovery expr at this level if we can preserve
14213 // the return type, otherwise we return ExprError() and let the caller
14214 // recover.
14215 auto BuildRecoveryExpr = [&](QualType Type) {
14216 if (!AllowRecovery)
14217 return ExprError();
14218 std::vector<Expr *> SubExprs = {MemExprE};
14219 llvm::for_each(Args, [&SubExprs](Expr *E) { SubExprs.push_back(E); });
14220 return CreateRecoveryExpr(MemExprE->getBeginLoc(), RParenLoc, SubExprs,
14221 Type);
14222 };
14223 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
14224 return CallExpr::Create(Context, MemExprE, Args, Context.VoidTy, VK_RValue,
14225 RParenLoc, CurFPFeatureOverrides());
14226
14227 UnbridgedCastsSet UnbridgedCasts;
14228 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
14229 return ExprError();
14230
14231 MemberExpr *MemExpr;
14232 CXXMethodDecl *Method = nullptr;
14233 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
14234 NestedNameSpecifier *Qualifier = nullptr;
14235 if (isa<MemberExpr>(NakedMemExpr)) {
14236 MemExpr = cast<MemberExpr>(NakedMemExpr);
14237 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
14238 FoundDecl = MemExpr->getFoundDecl();
14239 Qualifier = MemExpr->getQualifier();
14240 UnbridgedCasts.restore();
14241 } else {
14242 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
14243 Qualifier = UnresExpr->getQualifier();
14244
14245 QualType ObjectType = UnresExpr->getBaseType();
14246 Expr::Classification ObjectClassification
14247 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
14248 : UnresExpr->getBase()->Classify(Context);
14249
14250 // Add overload candidates
14251 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
14252 OverloadCandidateSet::CSK_Normal);
14253
14254 // FIXME: avoid copy.
14255 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
14256 if (UnresExpr->hasExplicitTemplateArgs()) {
14257 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
14258 TemplateArgs = &TemplateArgsBuffer;
14259 }
14260
14261 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
14262 E = UnresExpr->decls_end(); I != E; ++I) {
14263
14264 NamedDecl *Func = *I;
14265 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
14266 if (isa<UsingShadowDecl>(Func))
14267 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
14268
14269
14270 // Microsoft supports direct constructor calls.
14271 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
14272 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args,
14273 CandidateSet,
14274 /*SuppressUserConversions*/ false);
14275 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
14276 // If explicit template arguments were provided, we can't call a
14277 // non-template member function.
14278 if (TemplateArgs)
14279 continue;
14280
14281 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
14282 ObjectClassification, Args, CandidateSet,
14283 /*SuppressUserConversions=*/false);
14284 } else {
14285 AddMethodTemplateCandidate(
14286 cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
14287 TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
14288 /*SuppressUserConversions=*/false);
14289 }
14290 }
14291
14292 DeclarationName DeclName = UnresExpr->getMemberName();
14293
14294 UnbridgedCasts.restore();
14295
14296 OverloadCandidateSet::iterator Best;
14297 bool Succeeded = false;
14298 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getBeginLoc(),
14299 Best)) {
14300 case OR_Success:
14301 Method = cast<CXXMethodDecl>(Best->Function);
14302 FoundDecl = Best->FoundDecl;
14303 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
14304 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
14305 break;
14306 // If FoundDecl is different from Method (such as if one is a template
14307 // and the other a specialization), make sure DiagnoseUseOfDecl is
14308 // called on both.
14309 // FIXME: This would be more comprehensively addressed by modifying
14310 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
14311 // being used.
14312 if (Method != FoundDecl.getDecl() &&
14313 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
14314 break;
14315 Succeeded = true;
14316 break;
14317
14318 case OR_No_Viable_Function:
14319 CandidateSet.NoteCandidates(
14320 PartialDiagnosticAt(
14321 UnresExpr->getMemberLoc(),
14322 PDiag(diag::err_ovl_no_viable_member_function_in_call)
14323 << DeclName << MemExprE->getSourceRange()),
14324 *this, OCD_AllCandidates, Args);
14325 break;
14326 case OR_Ambiguous:
14327 CandidateSet.NoteCandidates(
14328 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
14329 PDiag(diag::err_ovl_ambiguous_member_call)
14330 << DeclName << MemExprE->getSourceRange()),
14331 *this, OCD_AmbiguousCandidates, Args);
14332 break;
14333 case OR_Deleted:
14334 CandidateSet.NoteCandidates(
14335 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
14336 PDiag(diag::err_ovl_deleted_member_call)
14337 << DeclName << MemExprE->getSourceRange()),
14338 *this, OCD_AllCandidates, Args);
14339 break;
14340 }
14341 // Overload resolution fails, try to recover.
14342 if (!Succeeded)
14343 return BuildRecoveryExpr(chooseRecoveryType(CandidateSet, &Best));
14344
14345 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
14346
14347 // If overload resolution picked a static member, build a
14348 // non-member call based on that function.
14349 if (Method->isStatic()) {
14350 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
14351 RParenLoc);
14352 }
14353
14354 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
14355 }
14356
14357 QualType ResultType = Method->getReturnType();
14358 ExprValueKind VK = Expr::getValueKindForType(ResultType);
14359 ResultType = ResultType.getNonLValueExprType(Context);
14360
14361 assert(Method && "Member call to something that isn't a method?");
14362 const auto *Proto = Method->getType()->castAs<FunctionProtoType>();
14363 CXXMemberCallExpr *TheCall = CXXMemberCallExpr::Create(
14364 Context, MemExprE, Args, ResultType, VK, RParenLoc,
14365 CurFPFeatureOverrides(), Proto->getNumParams());
14366
14367 // Check for a valid return type.
14368 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
14369 TheCall, Method))
14370 return BuildRecoveryExpr(ResultType);
14371
14372 // Convert the object argument (for a non-static member function call).
14373 // We only need to do this if there was actually an overload; otherwise
14374 // it was done at lookup.
14375 if (!Method->isStatic()) {
14376 ExprResult ObjectArg =
14377 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
14378 FoundDecl, Method);
14379 if (ObjectArg.isInvalid())
14380 return ExprError();
14381 MemExpr->setBase(ObjectArg.get());
14382 }
14383
14384 // Convert the rest of the arguments
14385 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
14386 RParenLoc))
14387 return BuildRecoveryExpr(ResultType);
14388
14389 DiagnoseSentinelCalls(Method, LParenLoc, Args);
14390
14391 if (CheckFunctionCall(Method, TheCall, Proto))
14392 return ExprError();
14393
14394 // In the case the method to call was not selected by the overloading
14395 // resolution process, we still need to handle the enable_if attribute. Do
14396 // that here, so it will not hide previous -- and more relevant -- errors.
14397 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
14398 if (const EnableIfAttr *Attr =
14399 CheckEnableIf(Method, LParenLoc, Args, true)) {
14400 Diag(MemE->getMemberLoc(),
14401 diag::err_ovl_no_viable_member_function_in_call)
14402 << Method << Method->getSourceRange();
14403 Diag(Method->getLocation(),
14404 diag::note_ovl_candidate_disabled_by_function_cond_attr)
14405 << Attr->getCond()->getSourceRange() << Attr->getMessage();
14406 return ExprError();
14407 }
14408 }
14409
14410 if ((isa<CXXConstructorDecl>(CurContext) ||
14411 isa<CXXDestructorDecl>(CurContext)) &&
14412 TheCall->getMethodDecl()->isPure()) {
14413 const CXXMethodDecl *MD = TheCall->getMethodDecl();
14414
14415 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
14416 MemExpr->performsVirtualDispatch(getLangOpts())) {
14417 Diag(MemExpr->getBeginLoc(),
14418 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
14419 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
14420 << MD->getParent();
14421
14422 Diag(MD->getBeginLoc(), diag::note_previous_decl) << MD->getDeclName();
14423 if (getLangOpts().AppleKext)
14424 Diag(MemExpr->getBeginLoc(), diag::note_pure_qualified_call_kext)
14425 << MD->getParent() << MD->getDeclName();
14426 }
14427 }
14428
14429 if (CXXDestructorDecl *DD =
14430 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
14431 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
14432 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
14433 CheckVirtualDtorCall(DD, MemExpr->getBeginLoc(), /*IsDelete=*/false,
14434 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
14435 MemExpr->getMemberLoc());
14436 }
14437
14438 return CheckForImmediateInvocation(MaybeBindToTemporary(TheCall),
14439 TheCall->getMethodDecl());
14440}
14441
14442/// BuildCallToObjectOfClassType - Build a call to an object of class
14443/// type (C++ [over.call.object]), which can end up invoking an
14444/// overloaded function call operator (@c operator()) or performing a
14445/// user-defined conversion on the object argument.
14446ExprResult
14447Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
14448 SourceLocation LParenLoc,
14449 MultiExprArg Args,
14450 SourceLocation RParenLoc) {
14451 if (checkPlaceholderForOverload(*this, Obj))
14452 return ExprError();
14453 ExprResult Object = Obj;
14454
14455 UnbridgedCastsSet UnbridgedCasts;
14456 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
14457 return ExprError();
14458
14459 assert(Object.get()->getType()->isRecordType() &&
14460 "Requires object type argument");
14461
14462 // C++ [over.call.object]p1:
14463 // If the primary-expression E in the function call syntax
14464 // evaluates to a class object of type "cv T", then the set of
14465 // candidate functions includes at least the function call
14466 // operators of T. The function call operators of T are obtained by
14467 // ordinary lookup of the name operator() in the context of
14468 // (E).operator().
14469 OverloadCandidateSet CandidateSet(LParenLoc,
14470 OverloadCandidateSet::CSK_Operator);
14471 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
14472
14473 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
14474 diag::err_incomplete_object_call, Object.get()))
14475 return true;
14476
14477 const auto *Record = Object.get()->getType()->castAs<RecordType>();
14478 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
14479 LookupQualifiedName(R, Record->getDecl());
14480 R.suppressDiagnostics();
14481
14482 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
14483 Oper != OperEnd; ++Oper) {
14484 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
14485 Object.get()->Classify(Context), Args, CandidateSet,
14486 /*SuppressUserConversion=*/false);
14487 }
14488
14489 // C++ [over.call.object]p2:
14490 // In addition, for each (non-explicit in C++0x) conversion function
14491 // declared in T of the form
14492 //
14493 // operator conversion-type-id () cv-qualifier;
14494 //
14495 // where cv-qualifier is the same cv-qualification as, or a
14496 // greater cv-qualification than, cv, and where conversion-type-id
14497 // denotes the type "pointer to function of (P1,...,Pn) returning
14498 // R", or the type "reference to pointer to function of
14499 // (P1,...,Pn) returning R", or the type "reference to function
14500 // of (P1,...,Pn) returning R", a surrogate call function [...]
14501 // is also considered as a candidate function. Similarly,
14502 // surrogate call functions are added to the set of candidate
14503 // functions for each conversion function declared in an
14504 // accessible base class provided the function is not hidden
14505 // within T by another intervening declaration.
14506 const auto &Conversions =
14507 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
14508 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
14509 NamedDecl *D = *I;
14510 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
14511 if (isa<UsingShadowDecl>(D))
14512 D = cast<UsingShadowDecl>(D)->getTargetDecl();
14513
14514 // Skip over templated conversion functions; they aren't
14515 // surrogates.
14516 if (isa<FunctionTemplateDecl>(D))
14517 continue;
14518
14519 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
14520 if (!Conv->isExplicit()) {
14521 // Strip the reference type (if any) and then the pointer type (if
14522 // any) to get down to what might be a function type.
14523 QualType ConvType = Conv->getConversionType().getNonReferenceType();
14524 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
14525 ConvType = ConvPtrType->getPointeeType();
14526
14527 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
14528 {
14529 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
14530 Object.get(), Args, CandidateSet);
14531 }
14532 }
14533 }
14534
14535 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14536
14537 // Perform overload resolution.
14538 OverloadCandidateSet::iterator Best;
14539 switch (CandidateSet.BestViableFunction(*this, Object.get()->getBeginLoc(),
14540 Best)) {
14541 case OR_Success:
14542 // Overload resolution succeeded; we'll build the appropriate call
14543 // below.
14544 break;
14545
14546 case OR_No_Viable_Function: {
14547 PartialDiagnostic PD =
14548 CandidateSet.empty()
14549 ? (PDiag(diag::err_ovl_no_oper)
14550 << Object.get()->getType() << /*call*/ 1
14551 << Object.get()->getSourceRange())
14552 : (PDiag(diag::err_ovl_no_viable_object_call)
14553 << Object.get()->getType() << Object.get()->getSourceRange());
14554 CandidateSet.NoteCandidates(
14555 PartialDiagnosticAt(Object.get()->getBeginLoc(), PD), *this,
14556 OCD_AllCandidates, Args);
14557 break;
14558 }
14559 case OR_Ambiguous:
14560 CandidateSet.NoteCandidates(
14561 PartialDiagnosticAt(Object.get()->getBeginLoc(),
14562 PDiag(diag::err_ovl_ambiguous_object_call)
14563 << Object.get()->getType()
14564 << Object.get()->getSourceRange()),
14565 *this, OCD_AmbiguousCandidates, Args);
14566 break;
14567
14568 case OR_Deleted:
14569 CandidateSet.NoteCandidates(
14570 PartialDiagnosticAt(Object.get()->getBeginLoc(),
14571 PDiag(diag::err_ovl_deleted_object_call)
14572 << Object.get()->getType()
14573 << Object.get()->getSourceRange()),
14574 *this, OCD_AllCandidates, Args);
14575 break;
14576 }
14577
14578 if (Best == CandidateSet.end())
14579 return true;
14580
14581 UnbridgedCasts.restore();
14582
14583 if (Best->Function == nullptr) {
14584 // Since there is no function declaration, this is one of the
14585 // surrogate candidates. Dig out the conversion function.
14586 CXXConversionDecl *Conv
14587 = cast<CXXConversionDecl>(
14588 Best->Conversions[0].UserDefined.ConversionFunction);
14589
14590 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
14591 Best->FoundDecl);
14592 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
14593 return ExprError();
14594 assert(Conv == Best->FoundDecl.getDecl() &&
14595 "Found Decl & conversion-to-functionptr should be same, right?!");
14596 // We selected one of the surrogate functions that converts the
14597 // object parameter to a function pointer. Perform the conversion
14598 // on the object argument, then let BuildCallExpr finish the job.
14599
14600 // Create an implicit member expr to refer to the conversion operator.
14601 // and then call it.
14602 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
14603 Conv, HadMultipleCandidates);
14604 if (Call.isInvalid())
14605 return ExprError();
14606 // Record usage of conversion in an implicit cast.
14607 Call = ImplicitCastExpr::Create(
14608 Context, Call.get()->getType(), CK_UserDefinedConversion, Call.get(),
14609 nullptr, VK_RValue, CurFPFeatureOverrides());
14610
14611 return BuildCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
14612 }
14613
14614 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
14615
14616 // We found an overloaded operator(). Build a CXXOperatorCallExpr
14617 // that calls this method, using Object for the implicit object
14618 // parameter and passing along the remaining arguments.
14619 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
14620
14621 // An error diagnostic has already been printed when parsing the declaration.
14622 if (Method->isInvalidDecl())
14623 return ExprError();
14624
14625 const auto *Proto = Method->getType()->castAs<FunctionProtoType>();
14626 unsigned NumParams = Proto->getNumParams();
14627
14628 DeclarationNameInfo OpLocInfo(
14629 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
14630 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
14631 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
14632 Obj, HadMultipleCandidates,
14633 OpLocInfo.getLoc(),
14634 OpLocInfo.getInfo());
14635 if (NewFn.isInvalid())
14636 return true;
14637
14638 // The number of argument slots to allocate in the call. If we have default
14639 // arguments we need to allocate space for them as well. We additionally
14640 // need one more slot for the object parameter.
14641 unsigned NumArgsSlots = 1 + std::max<unsigned>(Args.size(), NumParams);
14642
14643 // Build the full argument list for the method call (the implicit object
14644 // parameter is placed at the beginning of the list).
14645 SmallVector<Expr *, 8> MethodArgs(NumArgsSlots);
14646
14647 bool IsError = false;
14648
14649 // Initialize the implicit object parameter.
14650 ExprResult ObjRes =
14651 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
14652 Best->FoundDecl, Method);
14653 if (ObjRes.isInvalid())
14654 IsError = true;
14655 else
14656 Object = ObjRes;
14657 MethodArgs[0] = Object.get();
14658
14659 // Check the argument types.
14660 for (unsigned i = 0; i != NumParams; i++) {
14661 Expr *Arg;
14662 if (i < Args.size()) {
14663 Arg = Args[i];
14664
14665 // Pass the argument.
14666
14667 ExprResult InputInit
14668 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
14669 Context,
14670 Method->getParamDecl(i)),
14671 SourceLocation(), Arg);
14672
14673 IsError |= InputInit.isInvalid();
14674 Arg = InputInit.getAs<Expr>();
14675 } else {
14676 ExprResult DefArg
14677 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
14678 if (DefArg.isInvalid()) {
14679 IsError = true;
14680 break;
14681 }
14682
14683 Arg = DefArg.getAs<Expr>();
14684 }
14685
14686 MethodArgs[i + 1] = Arg;
14687 }
14688
14689 // If this is a variadic call, handle args passed through "...".
14690 if (Proto->isVariadic()) {
14691 // Promote the arguments (C99 6.5.2.2p7).
14692 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
14693 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
14694 nullptr);
14695 IsError |= Arg.isInvalid();
14696 MethodArgs[i + 1] = Arg.get();
14697 }
14698 }
14699
14700 if (IsError)
14701 return true;
14702
14703 DiagnoseSentinelCalls(Method, LParenLoc, Args);
14704
14705 // Once we've built TheCall, all of the expressions are properly owned.
14706 QualType ResultTy = Method->getReturnType();
14707 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14708 ResultTy = ResultTy.getNonLValueExprType(Context);
14709
14710 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
14711 Context, OO_Call, NewFn.get(), MethodArgs, ResultTy, VK, RParenLoc,
14712 CurFPFeatureOverrides());
14713
14714 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
14715 return true;
14716
14717 if (CheckFunctionCall(Method, TheCall, Proto))
14718 return true;
14719
14720 return CheckForImmediateInvocation(MaybeBindToTemporary(TheCall), Method);
14721}
14722
14723/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
14724/// (if one exists), where @c Base is an expression of class type and
14725/// @c Member is the name of the member we're trying to find.
14726ExprResult
14727Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
14728 bool *NoArrowOperatorFound) {
14729 assert(Base->getType()->isRecordType() &&
14730 "left-hand side must have class type");
14731
14732 if (checkPlaceholderForOverload(*this, Base))
14733 return ExprError();
14734
14735 SourceLocation Loc = Base->getExprLoc();
14736
14737 // C++ [over.ref]p1:
14738 //
14739 // [...] An expression x->m is interpreted as (x.operator->())->m
14740 // for a class object x of type T if T::operator->() exists and if
14741 // the operator is selected as the best match function by the
14742 // overload resolution mechanism (13.3).
14743 DeclarationName OpName =
14744 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
14745 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
14746
14747 if (RequireCompleteType(Loc, Base->getType(),
14748 diag::err_typecheck_incomplete_tag, Base))
14749 return ExprError();
14750
14751 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
14752 LookupQualifiedName(R, Base->getType()->castAs<RecordType>()->getDecl());
14753 R.suppressDiagnostics();
14754
14755 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
14756 Oper != OperEnd; ++Oper) {
14757 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
14758 None, CandidateSet, /*SuppressUserConversion=*/false);
14759 }
14760
14761 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14762
14763 // Perform overload resolution.
14764 OverloadCandidateSet::iterator Best;
14765 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
14766 case OR_Success:
14767 // Overload resolution succeeded; we'll build the call below.
14768 break;
14769
14770 case OR_No_Viable_Function: {
14771 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates, Base);
14772 if (CandidateSet.empty()) {
14773 QualType BaseType = Base->getType();
14774 if (NoArrowOperatorFound) {
14775 // Report this specific error to the caller instead of emitting a
14776 // diagnostic, as requested.
14777 *NoArrowOperatorFound = true;
14778 return ExprError();
14779 }
14780 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
14781 << BaseType << Base->getSourceRange();
14782 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
14783 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
14784 << FixItHint::CreateReplacement(OpLoc, ".");
14785 }
14786 } else
14787 Diag(OpLoc, diag::err_ovl_no_viable_oper)
14788 << "operator->" << Base->getSourceRange();
14789 CandidateSet.NoteCandidates(*this, Base, Cands);
14790 return ExprError();
14791 }
14792 case OR_Ambiguous:
14793 CandidateSet.NoteCandidates(
14794 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_unary)
14795 << "->" << Base->getType()
14796 << Base->getSourceRange()),
14797 *this, OCD_AmbiguousCandidates, Base);
14798 return ExprError();
14799
14800 case OR_Deleted:
14801 CandidateSet.NoteCandidates(
14802 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
14803 << "->" << Base->getSourceRange()),
14804 *this, OCD_AllCandidates, Base);
14805 return ExprError();
14806 }
14807
14808 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
14809
14810 // Convert the object parameter.
14811 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
14812 ExprResult BaseResult =
14813 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
14814 Best->FoundDecl, Method);
14815 if (BaseResult.isInvalid())
14816 return ExprError();
14817 Base = BaseResult.get();
14818
14819 // Build the operator call.
14820 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
14821 Base, HadMultipleCandidates, OpLoc);
14822 if (FnExpr.isInvalid())
14823 return ExprError();
14824
14825 QualType ResultTy = Method->getReturnType();
14826 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14827 ResultTy = ResultTy.getNonLValueExprType(Context);
14828 CXXOperatorCallExpr *TheCall =
14829 CXXOperatorCallExpr::Create(Context, OO_Arrow, FnExpr.get(), Base,
14830 ResultTy, VK, OpLoc, CurFPFeatureOverrides());
14831
14832 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
14833 return ExprError();
14834
14835 if (CheckFunctionCall(Method, TheCall,
14836 Method->getType()->castAs<FunctionProtoType>()))
14837 return ExprError();
14838
14839 return MaybeBindToTemporary(TheCall);
14840}
14841
14842/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
14843/// a literal operator described by the provided lookup results.
14844ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
14845 DeclarationNameInfo &SuffixInfo,
14846 ArrayRef<Expr*> Args,
14847 SourceLocation LitEndLoc,
14848 TemplateArgumentListInfo *TemplateArgs) {
14849 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
14850
14851 OverloadCandidateSet CandidateSet(UDSuffixLoc,
14852 OverloadCandidateSet::CSK_Normal);
14853 AddNonMemberOperatorCandidates(R.asUnresolvedSet(), Args, CandidateSet,
14854 TemplateArgs);
14855
14856 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14857
14858 // Perform overload resolution. This will usually be trivial, but might need
14859 // to perform substitutions for a literal operator template.
14860 OverloadCandidateSet::iterator Best;
14861 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
14862 case OR_Success:
14863 case OR_Deleted:
14864 break;
14865
14866 case OR_No_Viable_Function:
14867 CandidateSet.NoteCandidates(
14868 PartialDiagnosticAt(UDSuffixLoc,
14869 PDiag(diag::err_ovl_no_viable_function_in_call)
14870 << R.getLookupName()),
14871 *this, OCD_AllCandidates, Args);
14872 return ExprError();
14873
14874 case OR_Ambiguous:
14875 CandidateSet.NoteCandidates(
14876 PartialDiagnosticAt(R.getNameLoc(), PDiag(diag::err_ovl_ambiguous_call)
14877 << R.getLookupName()),
14878 *this, OCD_AmbiguousCandidates, Args);
14879 return ExprError();
14880 }
14881
14882 FunctionDecl *FD = Best->Function;
14883 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
14884 nullptr, HadMultipleCandidates,
14885 SuffixInfo.getLoc(),
14886 SuffixInfo.getInfo());
14887 if (Fn.isInvalid())
14888 return true;
14889
14890 // Check the argument types. This should almost always be a no-op, except
14891 // that array-to-pointer decay is applied to string literals.
14892 Expr *ConvArgs[2];
14893 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
14894 ExprResult InputInit = PerformCopyInitialization(
14895 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
14896 SourceLocation(), Args[ArgIdx]);
14897 if (InputInit.isInvalid())
14898 return true;
14899 ConvArgs[ArgIdx] = InputInit.get();
14900 }
14901
14902 QualType ResultTy = FD->getReturnType();
14903 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14904 ResultTy = ResultTy.getNonLValueExprType(Context);
14905
14906 UserDefinedLiteral *UDL = UserDefinedLiteral::Create(
14907 Context, Fn.get(), llvm::makeArrayRef(ConvArgs, Args.size()), ResultTy,
14908 VK, LitEndLoc, UDSuffixLoc, CurFPFeatureOverrides());
14909
14910 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
14911 return ExprError();
14912
14913 if (CheckFunctionCall(FD, UDL, nullptr))
14914 return ExprError();
14915
14916 return CheckForImmediateInvocation(MaybeBindToTemporary(UDL), FD);
14917}
14918
14919/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
14920/// given LookupResult is non-empty, it is assumed to describe a member which
14921/// will be invoked. Otherwise, the function will be found via argument
14922/// dependent lookup.
14923/// CallExpr is set to a valid expression and FRS_Success returned on success,
14924/// otherwise CallExpr is set to ExprError() and some non-success value
14925/// is returned.
14926Sema::ForRangeStatus
14927Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
14928 SourceLocation RangeLoc,
14929 const DeclarationNameInfo &NameInfo,
14930 LookupResult &MemberLookup,
14931 OverloadCandidateSet *CandidateSet,
14932 Expr *Range, ExprResult *CallExpr) {
14933 Scope *S = nullptr;
14934
14935 CandidateSet->clear(OverloadCandidateSet::CSK_Normal);
14936 if (!MemberLookup.empty()) {
14937 ExprResult MemberRef =
14938 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
14939 /*IsPtr=*/false, CXXScopeSpec(),
14940 /*TemplateKWLoc=*/SourceLocation(),
14941 /*FirstQualifierInScope=*/nullptr,
14942 MemberLookup,
14943 /*TemplateArgs=*/nullptr, S);
14944 if (MemberRef.isInvalid()) {
14945 *CallExpr = ExprError();
14946 return FRS_DiagnosticIssued;
14947 }
14948 *CallExpr = BuildCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
14949 if (CallExpr->isInvalid()) {
14950 *CallExpr = ExprError();
14951 return FRS_DiagnosticIssued;
14952 }
14953 } else {
14954 ExprResult FnR = CreateUnresolvedLookupExpr(/*NamingClass=*/nullptr,
14955 NestedNameSpecifierLoc(),
14956 NameInfo, UnresolvedSet<0>());
14957 if (FnR.isInvalid())
14958 return FRS_DiagnosticIssued;
14959 UnresolvedLookupExpr *Fn = cast<UnresolvedLookupExpr>(FnR.get());
14960
14961 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
14962 CandidateSet, CallExpr);
14963 if (CandidateSet->empty() || CandidateSetError) {
14964 *CallExpr = ExprError();
14965 return FRS_NoViableFunction;
14966 }
14967 OverloadCandidateSet::iterator Best;
14968 OverloadingResult OverloadResult =
14969 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best);
14970
14971 if (OverloadResult == OR_No_Viable_Function) {
14972 *CallExpr = ExprError();
14973 return FRS_NoViableFunction;
14974 }
14975 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
14976 Loc, nullptr, CandidateSet, &Best,
14977 OverloadResult,
14978 /*AllowTypoCorrection=*/false);
14979 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
14980 *CallExpr = ExprError();
14981 return FRS_DiagnosticIssued;
14982 }
14983 }
14984 return FRS_Success;
14985}
14986
14987
14988/// FixOverloadedFunctionReference - E is an expression that refers to
14989/// a C++ overloaded function (possibly with some parentheses and
14990/// perhaps a '&' around it). We have resolved the overloaded function
14991/// to the function declaration Fn, so patch up the expression E to
14992/// refer (possibly indirectly) to Fn. Returns the new expr.
14993Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
14994 FunctionDecl *Fn) {
14995 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
14996 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
14997 Found, Fn);
14998 if (SubExpr == PE->getSubExpr())
14999 return PE;
15000
15001 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
15002 }
15003
15004 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
15005 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
15006 Found, Fn);
15007 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
15008 SubExpr->getType()) &&
15009 "Implicit cast type cannot be determined from overload");
15010 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
15011 if (SubExpr == ICE->getSubExpr())
15012 return ICE;
15013
15014 return ImplicitCastExpr::Create(Context, ICE->getType(), ICE->getCastKind(),
15015 SubExpr, nullptr, ICE->getValueKind(),
15016 CurFPFeatureOverrides());
15017 }
15018
15019 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
15020 if (!GSE->isResultDependent()) {
15021 Expr *SubExpr =
15022 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
15023 if (SubExpr == GSE->getResultExpr())
15024 return GSE;
15025
15026 // Replace the resulting type information before rebuilding the generic
15027 // selection expression.
15028 ArrayRef<Expr *> A = GSE->getAssocExprs();
15029 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
15030 unsigned ResultIdx = GSE->getResultIndex();
15031 AssocExprs[ResultIdx] = SubExpr;
15032
15033 return GenericSelectionExpr::Create(
15034 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
15035 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
15036 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
15037 ResultIdx);
15038 }
15039 // Rather than fall through to the unreachable, return the original generic
15040 // selection expression.
15041 return GSE;
15042 }
15043
15044 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
15045 assert(UnOp->getOpcode() == UO_AddrOf &&
15046 "Can only take the address of an overloaded function");
15047 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
15048 if (Method->isStatic()) {
15049 // Do nothing: static member functions aren't any different
15050 // from non-member functions.
15051 } else {
15052 // Fix the subexpression, which really has to be an
15053 // UnresolvedLookupExpr holding an overloaded member function
15054 // or template.
15055 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
15056 Found, Fn);
15057 if (SubExpr == UnOp->getSubExpr())
15058 return UnOp;
15059
15060 assert(isa<DeclRefExpr>(SubExpr)
15061 && "fixed to something other than a decl ref");
15062 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
15063 && "fixed to a member ref with no nested name qualifier");
15064
15065 // We have taken the address of a pointer to member
15066 // function. Perform the computation here so that we get the
15067 // appropriate pointer to member type.
15068 QualType ClassType
15069 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
15070 QualType MemPtrType
15071 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
15072 // Under the MS ABI, lock down the inheritance model now.
15073 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
15074 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
15075
15076 return UnaryOperator::Create(
15077 Context, SubExpr, UO_AddrOf, MemPtrType, VK_RValue, OK_Ordinary,
15078 UnOp->getOperatorLoc(), false, CurFPFeatureOverrides());
15079 }
15080 }
15081 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
15082 Found, Fn);
15083 if (SubExpr == UnOp->getSubExpr())
15084 return UnOp;
15085
15086 return UnaryOperator::Create(Context, SubExpr, UO_AddrOf,
15087 Context.getPointerType(SubExpr->getType()),
15088 VK_RValue, OK_Ordinary, UnOp->getOperatorLoc(),
15089 false, CurFPFeatureOverrides());
15090 }
15091
15092 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
15093 // FIXME: avoid copy.
15094 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
15095 if (ULE->hasExplicitTemplateArgs()) {
15096 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
15097 TemplateArgs = &TemplateArgsBuffer;
15098 }
15099
15100 DeclRefExpr *DRE =
15101 BuildDeclRefExpr(Fn, Fn->getType(), VK_LValue, ULE->getNameInfo(),
15102 ULE->getQualifierLoc(), Found.getDecl(),
15103 ULE->getTemplateKeywordLoc(), TemplateArgs);
15104 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
15105 return DRE;
15106 }
15107
15108 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
15109 // FIXME: avoid copy.
15110 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
15111 if (MemExpr->hasExplicitTemplateArgs()) {
15112 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
15113 TemplateArgs = &TemplateArgsBuffer;
15114 }
15115
15116 Expr *Base;
15117
15118 // If we're filling in a static method where we used to have an
15119 // implicit member access, rewrite to a simple decl ref.
15120 if (MemExpr->isImplicitAccess()) {
15121 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
15122 DeclRefExpr *DRE = BuildDeclRefExpr(
15123 Fn, Fn->getType(), VK_LValue, MemExpr->getNameInfo(),
15124 MemExpr->getQualifierLoc(), Found.getDecl(),
15125 MemExpr->getTemplateKeywordLoc(), TemplateArgs);
15126 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
15127 return DRE;
15128 } else {
15129 SourceLocation Loc = MemExpr->getMemberLoc();
15130 if (MemExpr->getQualifier())
15131 Loc = MemExpr->getQualifierLoc().getBeginLoc();
15132 Base =
15133 BuildCXXThisExpr(Loc, MemExpr->getBaseType(), /*IsImplicit=*/true);
15134 }
15135 } else
15136 Base = MemExpr->getBase();
15137
15138 ExprValueKind valueKind;
15139 QualType type;
15140 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
15141 valueKind = VK_LValue;
15142 type = Fn->getType();
15143 } else {
15144 valueKind = VK_RValue;
15145 type = Context.BoundMemberTy;
15146 }
15147
15148 return BuildMemberExpr(
15149 Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
15150 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
15151 /*HadMultipleCandidates=*/true, MemExpr->getMemberNameInfo(),
15152 type, valueKind, OK_Ordinary, TemplateArgs);
15153 }
15154
15155 llvm_unreachable("Invalid reference to overloaded function");
15156}
15157
15158ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
15159 DeclAccessPair Found,
15160 FunctionDecl *Fn) {
15161 return FixOverloadedFunctionReference(E.get(), Found, Fn);
15162}
15163